Welllllll, I'd say, first thing, always re-read your posts for spelling and such before hitting submit. It's easy to get caught up in telling the story and miss typos and such. Also, if it's something you're really serious about, researching is good. I'm not saying things have to be perfectly, completely accurate, but it's easier to play a part if you know the things that person would know. If they're a fighter, know something about fighting, even if it's only the proper terms for moves, or if they grew up in a certain place or time period, it helps to know something about them. Little things like that can really make a difference.