Unless you're required to wear a suit for work, there are few times men usually find themselves wearing one. Most guys probably only own one suit, if they even own one at all. The great thing about a suit, however, is that you can dress it down and get a different outfit for any type of occasion simply by combining it with clothes you already have in your closet.
The key to a good suit, as with any item of clothing, is the fit. If the jacket is too big you end up looking sloppy, and if it's too small it looks like you're desperately trying to hang on to a time in your life when a slow metabolism wasn't on your radar. Get your measurements and buy a suit that fits. It's better to go big if you're in between sizes -- a tailor can alter it for you. Don't feel limited to only wearing it on special occasions. Breaking out the full arsenal on a Friday night just because you want to is never a bad move.
Related: How to Fit a Men's Suit
A tie or bow tie is a must if you're going for the formal look, but don't stop there. Wear a pocket square or tie bar to add some more details to your suit, just don't wear both at the same time because it will be too distracting. Put on a watch that matches the color scheme of the suit and you're good to go.
Lose the Tie
Heading out for post-work happy hour or meeting the in-laws and want to keep it classy yet comfortable? Lose the tie and unbutton a button or two, but don't expose the collar of your undershirt if you're wearing one. That's a no-no. Wearing a v-neck T-shirt can solve that problem. Don't untuck your shirt, keep it in your pants. Otherwise you might as well show up in your PJs.
Classy Weekend Warrior
This is one of the most versatile looks you can wear. Keep the suit jacket and add chinos, a gingham shirt and cool leather shoes and you can walk into any situation and not feel underdressed. Toss in a pocket square to give another splash of color. Even though you can never be overdressed, you can always ditch the jacket and roll up your sleeves if you need to get in a game of beer pong or go primal on some barbecued ribs. Again, untuck the shirt and you're on your own.
Are You a Jeans Kind of Guy?
If you love wearing jeans you can make it work with a nice collared shirt and tie. The jeans keep your look from being overly formal and a solid color tie adds some style. A knit tie would work great with this look as well. Make sure your jeans aren't baggy. Think about it, the suit jacket is going to have a tight fit, so wearing something baggy in the pants department will just look ridiculous. Don't be that guy. Put on slim-fit (not skinny) or straight leg jeans.
Fun and Casual
Don't feel like wearing a dress shirt? Put on a T-shirt or sweater and wear the suit jacket over it with a pair of jeans and sneakers. It's fun and casual way to make good use of your suit investment.