Rubber band makes a standard bar clamp a snap to use
I like to use the little F-style bar clamps, but sometimes it takes two hands to get them to grab. For one-hand clamping, I stretch a large rubber band around the jaws as shown, then pull the clamp open and hold the sliding jaw with my thumb. When I'm ready to clamp, I lift my thumb a bit and the jaw slides shut. A quick twist or two of the handle is all it takes to tighten the clamp.
—Malcolm Brennan, Edisto Island, S.C.