All you need are cans, some homemade wood clips and a chunk of 3/4-in. plywood screwed to a wall. To make the clips, rip a 3/4-in.-thick board into 1-3/8-in.-wide strips. Saw or rout a 3/8-in. x 1/4-in. rabbet along one edge. Drill 1/8-in. screw holes every 3/4 in. and then cut off 3/4-in.-wide clips. To mount the clips and cans on the plywood, screw on a clip, notch end down, then set a can on the clip and screw on a second clip overlapping the can's rim about 1/4 in.