Professional woodworkers often don't use pads on their clamps because they know how to set them up without marring the wood. But if you prefer to use them for pipe or bar clamps, you can buy some or make up your own. Scrap rubber, shoe soles, even old mud flaps, can do the trick. For pipe clamps, cut out a slightly undersize circle to fit over the pipe using a sabersaw. Next, cut out the perimeter about 1/8 in. oversize. Then make a slit in the pad bottom so it can stretch over the pipe without taking off the jaw end.
When making repairs or taking apart equipment, be prepared for the occasional dropped part. Clean off a section of your workbench and spread out a smooth shop or dish towel. The towel will keep errant small parts from rolling around on the floor and getting lost. For small jobs, even square shop rags will work; for larger jobs cover the bench with salvaged carpeting.