People make a lot of stupid fashion mistakes. I'm here to help people not make those mistakes with a few tips.
1. Lose the Undershirt
Undershirts make you look like an old man, much like Mitt Romney here. If you want to keep your outfit looking good than loose it.
2. Vary your color and fabric
Picture this, high school prom is around the corner and some guy thinks he's going to look great in an all matching neon suit. Please, stick to the classics when it comes to suit color. For a matter of fact don't even match your pocket square to your tie. You'll thank me later.
3. Get some collar stays
Collar stays will keep your shirt collar from bending all over the place. Keep a tight look with some collar stays.
4. Unbutton the bottom button.
As a general rule of thumb, just keep the middle button buttoned.
5. Get your suit fitted
75% of how good you look is based on fit (and the rest is confidence, usually). Just because the suit is "your size" off the rack doesn't mean it's fitted.