The Battle of Hoth goes down as one of the most iconic moments in Star Wars history for a few reasons.
It was the first time we caught a glimpse of the true might of the Imperial war machine on a scale the audience could comprehend and appreciate. The power to destroy a planet is great and all, but in terms of sheer scale, the Death Star is far too fantastical for us to wrap our heads around. "Oh, crap, it blew up a planet" is a little harder to understand than "Oh crap, that's enemy armor bearing down on me." The walkers themselves were still plenty fantastical, but in terms of scale, it's a lot easier to comprehend.
The coolness factor (no pun intended) of it all is also key to the Battle of Hoth's place in the heart of fandom. There's a reason it keeps being repeated time and time again in video games: it's freaking awesome. As frustrating as it is trying to weave the snowspeeder around the walker's legs in the Rogue Squadron games or the OG Battlefront, it's cool as hell to watch on the screen. As far as sci-fi battles go, it's one of the most epic that's ever been committed to film.
Thematically, it represents a low point for the Rebellion. They've been cornered, and the only chance they have for survival is to make a break for the stars. It's a moment of desperation, and of heroism, that resonates strongly with the viewers as the soldiers on the ground give their lives in a last ditch effort to delay Imperial forces until the evacuation can be completed.
But what if I told you that it didn't have to be?
Though the evacuation itself was extremely successful, the battle on the ground was a tactical mess. The Rebellion had all the keys for victory within their grasp. Instead of frittering away troops they couldn't spare in exchange for a handful of Imperial losses, they could have easily defeated the Imperial ground troops, turning the evacuation from a Hail Mary play to something far more like a tactical withdrawal.
NOTE: The original idea for this topic came from the Angry Staff Officer Blog. Their Warfighter: Hoth post does an excellent job of providing a general breakdown, and it's well worth the read. My goal is to approach the situation from the RP perspective. Certain areas, like breakdowns in chain of command, simply aren't relevant, while others, like making use of the terrain, require more attention. Our primary focus is on the Rebel side of things.

To start off, we're going to do a quick METT-TC (read: met tee cee) analysis of the situation. In case anyone is wondering, that's an acronym the Army uses during planning missions, providing the factors that need to be considered and their relative priority. The factors are: Mission, Enemy, Terrain,Troops Available, Time, and Civilian Considerations.
Mission: To delay the Imperial assault long enough to complete the evacuation of Echo Base.
Enemy: Imperial heavy armor, in the form of AT-AT walkers, augmented by AT-ST walkers and infantry. Different sources of varying levels of canon place all kinds of random crap on the battlefield, but for the purpose of this discussion, we'll stick to that. Though they had much more firepower at their disposal, the shield generator prevented most of it from being brought into play.
It's also worth nothing that Imperial commanders were notoriously unimaginative and risk averse. Due to Vader's penchant for Force choking anyone who failed to follow orders, upwards mobility for lower ranks often followed a senior officer's willingness to take chances that didn't pay off.
Terrain: Echo Base's northernmost entrance, the one that the Imperials were ultimately forced to attack, sat inside a deep draw, screened on either side by steep cliffs impassable to the lumbering walkers. In addition, the Imperials had to traverse several pieces of treacherous real estate, and many walkers were lost on the approach to Echo Base simply due to the terrain.
Troops Available: In addition to general infantry, Echo Base was home to a number of pilots and engineers. How do you figure the engineer part, you ask? Well, much of the base was carved out of the ice and snow in a short amount of time. They also had several heavy weapons platforms, including anti-infantry and anti-armor heavy cannon.
Time: The primary time consideration was the evacuation. Due to the size of the force the Imperials had on hand at Hoth, holding Echo Base indefinitely was never in the picture. However, the longer the initial assault could be delayed, the longer the Rebels would have to execute their evacuation plan.
Civilian Considerations: None. Wampas and tauntauns don't count.
You'll note that several of these factors worked heavily in the favor of the Rebellion.
Though the Empire had an insurmountable advantage in total troop counts, they were only able to effectively bring a small portion of that number to bear at any given time. Additionally, they should have been well aware of the fact that Imperial commanders tend to be rigid and unimaginative at the best of times.
Furthermore, the terrain heavily favored the defenders. Though the AT-ATs had little trouble walking on snow and ice so long as it was flat, their approach was heavily restricted, and easily predictable. There's no good reason why Blizzard Force should have even been able to get within firing range of the shield generator, save for the incompetence on behalf of the Rebels.
The lack of civilians also worked in the Rebellion's favor. Without having to worry about innocents getting caught in the line of fire, they were effectively able to use the whole battlefield however they saw fit. Needless to say, they did not.
So let's say you're the commander of the Rebel forces in Echo Base. How could best use those factors to your advantage?
Let's start with planning.
The lack of forward planning on behalf of the Rebellion is inexcusable. Yes, you can argue that they didn't have much warning of the impending assault, but that shouldn't matter, not one bit. Never, under any circumstances, should you construct a base without planning for the possibility that it might be attacked. This goes doubly if you have good reason to suspect that such an attack might occur. Despite the remote location, the Empire had a vast pool of resources to draw upon. Someone, somewhere, should have considered the possibility that they might have had to fend off an assault.
Before the first finger was lifted to build Echo Base, plans should have been drawn up for that exact occasion. The siting of Echo Base was impeccable, but beyond that, the Rebels wholly failed to take advantage of the multitude of natural advantages at their disposal.
Given that their shield protected them from orbital bombardment, and that the climate made a large scale infantry assault impractical, one could easily have predicted that the Empire would choose to go with armor. That's not to say that plans shouldn't have been in place for an infantry assault, but the primary focus should have been on armor. To that end, the Rebels failed spectacularly.
The whole of the potential engagement area around Echo Base was a sapper's playground. Ice is extremely treacherous to traverse with any sort of heavy armor, and the mountainous terrain dictated the path that the assault would have to take. Blizzard Force opted for a relatively direct route, all things considered, but there was still a wealth of terrain features that even a small team of combat engineers, or hell, bored infantrymen with a satchel of explosives, could have made use of.
The three places that stand out the most are the entrance to the Nev Ice Flow from Kerane Valley, the Nev Ice Flow, and the draw that led into Echo Base.
The entrance from the valley onto the ice flow was steep enough that the AT-ATs had to use switchbacks to climb it safely. Though this location was too far away from Echo Base to effectively be supported, a great deal could have been done to make it effectively impassable before the battle even started.
The most obvious choice of obstacle would be to hollow out pockets under the ice in critical locations. Though the ice would still appear stable on the surface, the first walker to step foot on one of those pockets would have tumbled through. Even if the crew survived, it would still be a demoralizing loss for Blizzard Force. Instead of plodding along up onto the ice flow, they would have been forced to either stop and send out scouts to test the ice, or turn back and find another route.
Given that the Rebels had access to equipment that could tunnel through the ice, there's no reason that this particular section shouldn't have been honeycombed with a network of hollows and tunnels that undermined, literally, the easiest route onto the flow.
Once out onto the Nev Ice Flow itself, the shenanigans could have begun in earnest. Similar networks of tunnels could have severely restricted movement, and what's more, could have herded the Imperial armor to just about anywhere the Rebels wanted. Their heavy weapons might have been unable to penetrate the armor of the walkers, but a walker that can't move because its front legs are buried up to the shoulder in ice and snow doesn't do anyone any good. Additionally, those tunnels could have allowed for free and unrestricted movement of combat engineers, so long as they were cautious not to get crushed. Though the walkers themselves were heavily armored, their undersides were demonstrably less so. Liberal use of mines could have further crippled Blizzard Force.
Since Imperial commanders who fail to complete their objectives tend to have short survival rates, one could reasonably assume that, once it became clear that AT-ATs couldn't reach the objective without sustaining unacceptable casualties, General Veers would have essentially one option left. His only hope at this point is to disembark his infantry, and pray to the Force that the AT-STs could traverse the remaining distance to the entrance of Echo Base without falling prey to the traps that crippled his AT-ATs in order to provide support.
This is where things would get really bad.
The draw leading up to Echo base was surrounded on both sides by steep mountains, effectively limiting the avenues of approach for troops on foot. There's an alternate path slightly to the east, but it's also a longer path, and that means more time. The longer the assault takes, the longer the Rebels have to evacuate. That's not to say that it shouldn't be defended as well, but the safe bet is that the frustrated and demoralized Imperials are going to go for the quickest route possible, lest they be Force choked into oblivion.
This draw is where the Rebel infantry should have really come into its own. Sniper and heavy blaster teams up in the hills could have fired down on the approaching Imperials with near impunity. The anti-vehicular cannon that were so ineffective against the AT-ATs would have had a field day with the much lighter armor of the AT-STs, assuming any were able to make the trip.
Meanwhile, instead of a single, linear trench out in the open that did the Rebels no good whatsoever, a carefully planned network of trenches could have allowed them to retreat in an orderly fashion, without ever having to expose themselves to enemy fire. The downside is that such a network works for the enemy just as well, should they manage to gain entry, but careful placement of mines and traps could have made it into the sort of nightmare that lives on in military legend, spoken of only in hushed whispers.
But what about Imperial reinforcements?
Well, what about them? The Rebels' shield prevented them from landing directly, and any reinforcements would have to face the same problems that Blizzard Force faced. Given that they were only expecting light resistance, it would likely take them some time to build up any proper sort of armored response, and even if they took a different route, the other possible avenues of approach were even more prone to sabotage.
If they did manage to somehow get troop transports through the shield, the Rebels' snowspeeders could have made short work of the unescorted transports; it was made clear from the beginning of the movie that starfighters weren't much good in the cold of Hoth.
So what's the lesson to be learned here?
Planning, my friends, is everything. As the saying goes, proper planning prevents piss poor performance. Granted, I've the benefit of hindsight in coming up with all of this, but consider this: the whole of the plan took me about an hour to cook up. It might take a few days to properly set up, maybe a week or two at the most. What's more, I'm not a defensive planner, I'm an artilleryman with access to an overhead map and an overactive imagination.
Even the Rebellion, who was so short on manpower that they were willing to brevet a smuggler to general, should have at least one person whose sole job is to plan out stuff like this. Preferably a small team of someones, with enough rank behind them to get things done.
Compared to some of the battles that occur in RP, especially in invasions, the Battle of Hoth was a small scale event. Both sides were armed with third rate technology compared to the stuff we churn through the Factory on a daily basis.
All too often, ground battles become numbers games, where writers throw jumbles of troops at each other with no real plan other than to smash each other to pieces. When that happens, all that nifty technology just ends up being another inch or two added to the writers' e-penis, and the inevitable pissing contest is about as much fun as a literal one.
Instead of taking that route, take a step back and plan ahead.
If you're on the receiving end and you get to choose where your forces are situated, find a map and plan out defenses. Think to yourself "how can I make this as difficult as possible, short of being an ass OOC?" All is fair in love and war, and there's nothing stopping you from using your imagination. Your opponent might curse your name for making them work so hard, but so long as everyone is writing fairly, it's a lot more fun that way than the traditional measuring of virtual cocks.
If you're attacking a well defended position, taking a step back to plan is even more important. Ask yourself what you would do in their shoes to make your life hell, and then come up with inventive countermeasures. Again, so long as both sides are taking steps to ensure that they're writing fairly, you might actually find yourself having fun.
This concludes the opening lecture of the Chaos War College. I realize it's a bit wordy, but hey, no one has ever accused me of being economical with my writing. As always, if you've any questions or comments, please feel free to post them below, but don't be an ass.