Crafty DIYers can use plastic cups to create homemade party lights. First, grab a string of lights and as many plastic cups as there are bulbs in the string. Drill a hole into the bottom of each cup. Then, one by one, push the base of each bulb into the hole, with the bulb sitting inside the cup and the base sticking out. Screw each bulb back into the string of lights; the screwed-in bulbs will hold the cups in place. Hang the lights for a fun, festive vibe.