Most Helpful Girl
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The fit of your clothes has a lot more to do with how you look than what you're wearing. It's almost always good to wear clothes that are tight fitting to your body (though maybe not skinny jeans). You can go too tight however; if you are getting the X shaped wrinkles around your buttons, you've gone too far.
I also recommend against t-shirts print on them, and any clothes with a pronounced logo. You're not some company's billboard. No matter how supposedly nice the brand is, it's just tacky.
Getting away from clothes, make sure you're decided on how you want to have your facial hair. Clean shaven, stubble, a full beard, it doesn't matter. Just shave or trim frequently, so you don't end up between styles, and looking unkempt.