The handy Miter Clamp Pliers. It takes a pretty strong thumb to open our miter clamps wide, (they will open nearly two inches by the way). Many users, including lots of big strong guys, like the ease of operation that the plier allows. There is no strain in the hand with the plier so you can calmly place the points exactly where you want them. If you use the clamps a lot and find that it pains the thumb, order a plier. They make applying and removing miter clamps easy.
Warning: May cause cancer www.p65warnings.ca.gov