Use a serrated knife or jigsaw to cut the patterns. If using a jigsaw, drill a hole first, then insert the jigsaw blade before turning it on. On each pattern, leave two stabilizers to help handle the weight of the other pumpkins (so it doesn't fold down on itself).
Paint two zigzag patterns above and two below the cut-out pattern, using four different paint colors. Repeat on the other two pumpkins. We put each color in the same exact location on each pumpkin. Let the paint dry completely.
Add the battery-operated lights to the inside of each pumpkin. Tape them in place if they move around too much. Then restack the pumpkins. Add something fun around the base like moss-covered rocks.