Presentation is a big thing for me, if someone's willing to put in the effort to make a nice, well constructed OOC and CS Template, i'm much more likely to give the RP a go. To me, the more effort put into the set up makes me think the GM will put in more effort to the RP itself.

The character sheet is probably the big one, I like to make character sheets and I like to read them, so I like nice looking, long and detailed ones. Even if I like the look of an RP itself, whether or not I actually give it a go comes down a lot to the detail and style of the CS.