I'm my writer's main here so the change is really subtle. Curupira is more childish, silly and very focused on certain people (protective of them) than I am so anything too much is Curupira. In serious threads, naturally, its the writer who's talking but if we get a little too serious, I either put it in brackets or make note of being OOC. I like to warn people.
But expect the character first, I like to let them roam free and explore conversing with outs through the out of character forums. None of it is of course canon or historically documented for her but it's a way of figuring out my character, kind of. This generally applies to all of mine, expect maybe some that have their own style (see post above).