Drill a hole (approx 1/4-1/2" wide) in the bottom of all 50 cups. You can stack and do several at a time. Test to make sure 2 lights will fit through hole. Snug is good.

Divide cups into two groups of 25. Each group makes half a ball.

If using zip-ties, punch 4 holes in tops of 25 cups (just under the raised lip) with equal distance between holes. Each hole has a hole opposite it.

Just eyeball placement of the holes. They don't have to be perfect.

If stapling, skip this step.

Arrange 12 cups in a circle. If 12 cups does not make a circle, your cups aren't the right size.

Clothespins hold the cups in place while you work but they're optional.

Using zip-ties, fasten each cup to its neighbor, by inserting a zip-tie through two holes. Pull the zip-tie closed but DO NOT TIGHTEN IT ALL THE WAY. (see photo at left.) When all cups are connected, cinch zip-ties tight, one by one, making sure that the cups stay flat in a circle. Trim zip-ties.

If stapling, attach each cup to its neighbors using two staples, top and bottom.

This is Layer One.

Layer Two has 9 cups. Lay a cup on top of Layer One. Line up the holes and zip-tie it to the bottom cup. DO NOT PULL TIGHT.

Go all around the circle, adding one cup at a time and zip-tying it to the cup it sits on. When all 9 cups are in place, then attach each cup to the one next to it. Every cup in the second layer will be attached at three points (to cup below and cup on either side.) Keep the hole punch handy: you may need to repunch if holes don't line up. When Layer Two is set, cinch zip-ties tight and trim.

If stapling, staple 9 cups of Layer Two to each other and to Layer One.

Fit last 4 cups into the space open at the top of dome, then join them to neighboring cups. Each cup will be attached at four points to adjoining cups. Do not tighten the zip-ties all the way until all of them are in place. Then cinch tight and trim.

If stapling, staple each cup in place at top and bottom to as many cups as possible.

This is Layer Three.

Half the ball is done! Now you're ready to start threading lights.

NOTE: Once lights are in, some people hotglue them into the cups so they won't slip out.

IMPORTANT! TEST LIGHTS BEFORE YOU INSERT THEM.
To insert lights: Start at prong end of the cord. Insert the two lights closest to prong into a cup in Layer One. (The prong will then hang out when you put the two halves together.)

Put two lights in each cup. Work your way around the ball-half, zigzaging from outer cups to inner cups and back. You want to end up on Layer One, at the cup next to one you started with.

Work slowly, careful not to skip a cup or miss a light. If you crack a cup, that's ok.

On the second half, insert lights starting from the opposite end of the cord (the plug end.) Start with any cup but make sure you finish on Layer One. (If you plan to hang several balls together, make sure the plug end hangs out between the cups, as well.)

Have clothespins ready to clips halves together once lights are in place.

Press the two halves together, making them fit snugly. Line up holes and attach with zip-ties. Pull tight and trim.

Or staple.

( Photograph does not show clothespins, but they make this step much easier by showing clearly where halves need to be joined.)

I make a hanger for my sparkleballs with a bit of chain and two "s" hooks. Choose the top of your sparkleball. Melt a hole between two well-connected cups. Insert one "s" hook into the hole and close. Add chain and second "s" hook.You can also use clear fishing line, ribbon, wire coat hangers to hang sparkleballs.

Plug in and enjoy!