1. Learn to spot the telltale signs of an ill-fitting jacket.
If the shoulder has a divot, the coat is too wide; if it forms an X shape when buttoned, it's too snug.
2. Remember it's always acceptable to fasten the middle button on either a two- or three-button jacket.
Fastening the top button is optional with a three-button jacket, but under no circumstance should you fasten the bottom button with either jacket option.
3. Like with a single-breasted suit, don't fasten the bottom button on a double-breasted suit.
4. In terms of length, the suit jacket should reach the knuckles of your thumb.
5. Pinstripes on a suit should be subtle, unless you are going for the Halloween mobster look.
6. With few exceptions, horizontal stripes are very hard to pull off, so proceed with caution.
7. When sitting, ALWAYS unfasten all the buttons on your jacket.
8. If you can only have one suit, opt for charcoal.
9. Your pants should fit comfortably, and you should be able to fit one finger in your waistband.
10. Pants should have one break at the top of the shoe or heel, and your socks should not show while standing...
11. ...but if you want a modern look you can have them tailored a little shorter.
12. There are many different types of lapels...
...but thin lapels with a notch are a more modern/popular look.
13. Vests are a great way to dress up a suit.
14. Your tie should just reach the belt or waistband of your pants, not shorter and certainly not longer.
15. And it should always be darker than your shirt.
16. A tie's width at its widest point should always match a lapel's width at its widest point.
17. For a more formal look, go with the Windsor knot when tying a tie.
18. A tie bar is a great way to add a personal touch to any suit.
19. Cuffs are an important part of your suit, and about half inch should show when standing.
20. Seersucker suits are great for warmer weather, but should only be worn when it's hot out.
21. Pay attention to the back of your suit.
22. When wearing a suit, abstain from a sports watch and opt for a traditional piece with either a metal or leather band.
23. If you choose to go tie-less with a suit, opt for a smaller collar so it doesn't get stuck under or over the lapel.
24. If you don't feel like wearing a belt, suspenders are a stylish alternative to keep your pants up.
25. Above all, get your suit tailored!
