The Sleeveless Jacket
No sleeves? No problem. All the polish of a blazer with none of the heat.
Steal: Don't try to survive summer without a khaki jacket: It defines the shoulders, pares the waist, blends with everything. Layer it over a shell if you like your biceps; over something with sleeves if you don't. Top, Magaschoni; skirt, Hanii Y. Rafaella; jacket, $79, MyShape.com
Splurge: Faultless cut and intriguing texture—thin ombré silk with a bit of shine—make this vest the perfect finishing touch. Dress, Thakoon; necklace, Gemma Redux; belt, Melamed; jacket, Vera Wang, $1,095, 212-382-2184
Good Deal: Handsome between-seasons tweed keeps company with turtlenecks or tees, twill trousers or white jeans. Necklace, Roberta Freymann; dress and belt, Akris; jacket, Cynthia Steffe, $265, Neiman Marcus, 800-365-7989