I probably have well over a hundred different types of clamps but the ones that get the most use are the ones made using the old spring loaded clothes pins The next most used are the bar clamps, I have about 12 of the 6 inch ones and 6 of the longer (up to 36 inches) and all get a fair amount of use. I never use pins unless there is no other choice as it can weaken the wood. Several bags of lead shot also get a lot of use, those about 12 inches long and a diameter of about 1.5 inches are ideal. Of course the old binder clips from the stationary department get a lot of use too.