I'm a pretty classy guy when it comes to dressing up, and youre not a bad looking dude at all. All it takes is a little work.
Start buying Well/Tight fitted jeans, with some casual shoes, like Nautica Sperry's, Puma's, Casual-ish Dress shoes, well fitted shirts with a unique look to them (Check out Urban Outfitters, H&M, Ben Sherman brand, online T-shirt companies ect.) Whatever floats your boat, make it unique, not cliche average joe shit. Whether its a more clean look, indie-vintage look, or just straight class with the suits and colorful dresshirts and ties. For the class, check out Express. Make sure nothing is baggy.
For Jewelry, dont over-do the rings. 1 or 2 is fine. For a necklace, wear a choker. something that goes nicely around youre neck.
Get rid of the headband. Get a hat. not a baseball hat. a legit, classy hat. That is if you want head apparell. I say, go to a hair stylist, and chop the hair. Grow some sideburns, neatly trimmed, and shaped, and for a hairstyle, for your face shape a lot can work. You want to make your face look a little bit longer so take the sides down short and put the top up. Phauxhawk = perfect example. A buzz could work too.
Add some highlights (optional).
Get a tan. Every man and human being on this fucking planet looks better with a tan.
Get all this done and we'll go into bigger detail. At first you may be against these ideas and feel uncomfortable because youre not use to doing it, and coming out of youre shell like this is weird but remember, we are here to help, especially me. So after all this is done, we'll get more specific.

Happy Sarging.
P.S.Just a look in the magazines chicks look at, that is what they look for physically.