Okay, this is a simple hack, even dull by most standards, but it's the hack tool I use more than any other. Because it's almost always attached some piece of gear, and it actually works.
I had connections that slip. Turn. Droop. Fall off. Too many 1/4 inch screws don't have sufficiently sticky pads to keep things from slipping/twisting/spinning. When I attach two pieces of equipment together, I want them to stick. In place. You know, like a locking washer would do. But we don't have locking washers in photography, we have pads that harden and become smooth. So here's a $7 solution.