I tend to dress comfortable and casual but dressed up enough that it looks like I'm out for a night of fun (i.e. looking like I could have been at the club in the casino or the restaurants and after a few drinks wanted to stop in and stack some chips baby!) This helps me come across as I want to come across, things like hoodies and headphones are dead giveaways that the player is at least a somewhat thinking poker player.
Patience and discipline are two skills you must master to succeed at poker long term.
The way you dress also effects how your opponents think of you. People judge books by it's cover. Think of what do you want your opponent to think of YOU whn he sees you for the first time. And dress up!
If you are younger and moderately good, then dress as out of place as possible. Out of place meaning dress like you dont belong there of like a typical hollywood envisioned poker player (visor, dorky tshirt, and take like you think you know whats going on... but be incorrect. Oh and talk mad smack how you watch a lot of twitch poker).
If.you are middle age or older and good at poker, look as middle aged or older as possible. This way when you 3b light the assume you have the goods every time.
If you're a rec player, regardless of age. Dress comfortably and have fun.
So my real answer. I generally am a tight player. When I went to the casino and was younger I generally dressed sloppy and wore a stupid hat so that people assumed I was one of those young loose players. I would find I got called a lot more. Now I have loosened up my game some and look for chances to steal from the older tight players. Now I try to look very respectable so that my raises may hopefully garner more respect than they should.
Above all though dress comfortable. You don't want your dress to keep you from playing optimal poker.