Heat or a safety pin can tighten loose swimsuit elastic without sewing.

Yes, you have two good options — and both take about five minutes.

First, try heat. If the elastic is synthetic (most swimsuit elastic is), hit it with a hair dryer on high for 30 seconds to a minute, then let it cool flat. Repeat once or twice. The heat can shrink the elastic slightly, pulling the leg or back opening tighter. Works better on older elastic that has stretched out from years of chlorine.

Second, the safety pin trick. Find the opening in the casing (usually near a seam), pull the elastic out a bit, and pin it to itself at a shorter length. Then tuck the pinned end back inside the casing. You won