One way to prevent half the beach from getting in your suit is to choose the right size swimwear.

“Most of us wear one size larger than we should, thinking it will provide more coverage, but it gives only a saggy behind and more space for sand to get in,” says Gili Rashal, editor in chief of the fashion website The Tip Jar (www.thetipjar.com).

Should you become a human sand trap, “wade into the water waist or chest deep and rinse out,” says image consultant and etiquette expert Samantha von Sperling, director of Polished Social Image Consultants, a New York City–based image-consulting firm. Can’t get wet again? Tie a beach towel around your chest and maneuver your suit to purge the sand. Don’t worry about looking like you’re doing the Watusi in a toga. “Sand is part of going to the beach — we all have to live with it,” von Sperling says.