A great suit will give you a gentlemanly look only when you take care of the untold rules involved in it.
The width of lapels should match the width of the tie and opt for trendy thin lapels. Choose a pocket square that doesn’t match with the tie in pattern or fabric. The shoulder pad should always end with your shoulders. Also make sure that the gap between the lapel and collar isn’t too much and the shirt collars aren’t exposed too much. Prefer a charcoal or grey colored suit over black except for funerals. Though a matching shoe is not absolute, it is a safe bet to select a shoe from a formal black, more relaxed brown and a playful burgundy depending on your mood and occasion. You shouldn’t pair brown suits with black shoes, charcoal grey suit with brown shoes and black suit with any shoe other than black color. Remember to wear a fairly thin belt with the same color of the shoes. Single-button peak-lapel jacket with a double vented back is trendy and unbutton it always before sitting down in order not to ruin it. A double-button, notched lapel jacket is more preferred in formal business gathering. The top button of a double-buttoned suit should be above the navel; middle button in the case of three-buttoned suits.
Your flat hand should slip easily under the lapels with a snug feel. Keep the bottom button unbuttoned when you wear a vest and are best worn with single-breasted suits. The bottom of your jacket should be even with your knuckles and the shirt cuff should be visible by half inch. The pant hem hitting the top of the shoe without covering the laces will give a trendy look. Wear an undershirt with a deep neck that doesn’t peek through if you sweat a lot. The socks should be lengthy enough to prevent your legs from getting exposed when you sit down.