I'm going to post a couple examples here...
Use third person perspective, and make speech bold with the [b] tag.
In combat, it also helps to summarize your actions at the end of your post. Action summary and any other OOC notes should be in blue with the [ooc] tag.
It doesn't hurt to go ahead and roll damage if your attack might hit, that way you don't have to post again once the GM says you hit. However, in general you want to leave the descriptions of your actions open-ended, so the GM can tell you the results.
