Make a backyard bowling alley. Add food coloring to clear plastic bottles of water. Use party streamers as lane margins. Add glow sticks for night bowling. (These would make great outdoor table nightlights also with the glowsticks, gonna try it!
Awesome idea:birthday party decor,take diffrent color table cloths and tape them to to ceiling like that. Then tie 3 diffrent color balloons together and tape them to another set of balloons then tape the all the balloons in the middle of the table cloth.