1. Ditch your been-there-done-that khaki suit for a navy cotton two-button, which offers the same relaxed comfort but more polish. It's versatile enough to be appropriate for both formal ceremonies and late-night celebrations. Blazer ($298), pants ($158), and pocket square ($42) by J. Crew. Shirt ($349) by Kitsuné. Tie ($125) by Black Fleece.
2. An unlined suit with a breathable silk-cotton construction will keep you cool and composed on even the warmest day. Play up its simple good looks with a classic white shirt and knit tie. Blazer ($2,549), pants ($818), and belt ($500) by Louis Vuitton. Shirt ($395) by Boglioli. Tie ($40) by Tallia Orange. Pocket square ($140) by Tom Ford.
3. You can break a tuxedo into separates just as you would a suit. A pale-blue one-button tux jacket paired with tapered black trousers creates a look that's both traditional and of-the-moment. Blazer ($1,925) and shirt ($375) by Michael Bastian. Pants ($595) by Maison Martin Margiela. Bow tie ($135) by Brioni. Pocket square ($55) by Alexander Olch.
4. A double-breasted suit in a narrow modern cut (call it one-and-a-half-breasted) straddles the line between formal and fun. Its trim fit lets you wear it unbuttoned without swaths of material flapping around you, so it's perfect for the dance floor. Suit ($3,740), shirt ($475), tie ($205), and pocket square ($135) by Brunello Cucinelli.