They're sexy, they're bold—but strap-free dresses are tricky unless you've got a grip on the proper fit. Here, some advice from fashion guru Tim Gunn (Tim Gunn's Guide to Style, on Bravo) and Victoria's Secret spokesperson Monica Mitro.
Assess Your Chest...
...and support yourself accordingly. Small-busted women find strapless easier because they don't need serious undergarments, says Mitro. Gunn thinks a curvy figure is an advantage: "Your natural shape reinforces the construction of the dress."
Look for Boning on the Bodice
"A proper, quality-infused strapless dress retains an hourglass shape even on the hanger," Gunn says. "No shapeless sacks!"
Wear a Bra
Even if a dress has plenty of infrastructure, spilling over could be a possibility. "If the dress alone is providing you with support, that's risky," warns Gunn. Mitro recommends push-up technology like underwire and plenty of room (you might have to go up a cup size).
Check for Slippage
When you're in the dressing room, raise your arms and bend over to make sure you don't fall out. Sit down to test for comfort (boning can jab you under the arms). And scrutinize your rear view: An ill-fitting bodice can pinch the skin, causing bulges at the back and sides.