1. The width of the tie should match the width of the lapel.
2. In general, thin lapels are more modern. Wide lapels are more old-school, Mad Men style.
3. A pocket square adds an extra level of polish, but make sure it doesn’t match your tie in either pattern or fabric choice.
4. When buying an off-the-rack suit, the number one thing to check is how the shoulders fit.
5. A collar gap between your jacket’s lapels and your shirt’s collar can signify an ill-fitting jacket.
6. Opt for a charcoal or gray suit over black, unless you’re attending a funeral.
7. Your belt should be fairly thin and the same color as your shoes.
8. You should match your shoes to the color of your suit using this guide
9. Double vents in the back are more modern and fashionable.
10. For a more casual, trendy look, opt for a single-button peak-lapel jacket.
11. If you’re going for more formal business attire, opt for a double-button, notched lapel jacket.
12. The Savile Row Fold keeps your dress pants from falling off the hanger.
13. You should be able to slip your hand between your chest and your buttoned jacket such that it feels snug, but with room to move.
14. Always unbutton your suit before sitting down, or you risk ruining it.
15. The top button of a two-button (or the middle button of a three-button) should fall at or above the navel.
16. Always go with the classic windsor knot for your tie, but use the size of your head to determine whether you should go half or full windsor.
17. If you’re wearing a vest, always keep the bottom button unbuttoned.
18. There are practical reasons for vests beyond just how they look.
19. Sleeve cuffs should be exposed about half an inch.
20. When you get your suit home, you’ll need a seam ripper or a small, sharp pair of scissors.
21. Make sure that your socks are long enough that there’s no exposed leg when sitting down.
22. Your tie should always be darker than your dress shirt.
23. The suit jacket should be just long enough to cover your pants zipper and butt.
24. Your tie should JUST reach the waistband of your trousers, or be slightly shorter.
25. For a more fashion-forward look, the pant hem should hit right at the top of your shoe.
26. If you sweat a lot, wear an undershirt.
27. Finally, go for the dimple.