It all starts with Richard Holdman's idea: http://www.holdman.com/christmas/star/ But I didn't want one quite that big. So I first decided to make one with C7 bulbs instead of C9's. From there I drew out the plan and figured out about where the lights should go and how many I was going to need. From there I figured out what size the star should be and so off I went!
I pretty much followed his plans and making it. However, since mine was smaller and I didn't use the same thickness board, I had to figure out those details on my own.
I first got a piece of 3/8" plywood about 3ft by 4ft. I then used a projector to cast the pattern on the board and traced the pattern.
Then I cut out the patterned star:
Next was drilling all the holes. This is a two part process when using the C7 or C9 bulbs. You first drill a larger hole to fit the socket into that gives just enough thickness left to allow the bulb to be screwed in and make contact but not be loose. This takes trial and error on the scrap material. Just keep trying various depths of each bit to get the right combination. With C7's the depth is about 1/8" on the larger bit.
Since I used thinner plywood, it became flimsy and delicate with all the holes in it. So I wrapped the top and bottom points of the star with flat aluminum stock to keep them rigid and used angle stock on the back to further stiffen the two points. You can also see the step where the socket rests in this picture.
Lastly was just painting it with multiple coats of outdoor flat black paint and placing all the lights. Since these are C7's in parallel circuits, it's easy to cut and splice the lights as needed to make up the three channels. You'll also notice there are four wing nuts seen here. These attach to a frame on the back side used to space the star away from the pole it's mounted to.