To get some easy kills with claymores, place them on sidewalks or at locations that would otherwise seem "obvious". Everyone always expects claymores to be just around a corner or in a doorway. However very few players expect to see one laying out in an open area. One such example is in the Crash level. Near the helicopter, place a claymore on the ground outside where people are always running around. Because they are running, there is a good chance they will run past and trigger it. By the time they realize their mistake, it will be too late.