So this is what I'm currently using to hold all of my "normal" earrings (posts and dangles)....
As you can see, it's a basic square-based pyramid shape. I used leftover base molding from a house renovation project for the frame. The bottom pieces are about 6" long and 1" high, and the sides are about 7.5 x 1".
Then I used a 1/16 drill bit to drill holes along the bottom and sides for post earrings. I staggered them so that larger earrings could fit on the top row without blocking the holes to the lower ones. I also drilled some holes in the sides for even larger earrings.
When all of your pieces are drilled and sanded, assemble them with hot glue and then spraypaint if desired.
I then strung embroidery floss around the inside of the boards so I could hang danglies too. Use a dab of hot glue and make sure you pull the string taut so it doesn't sag too much when you put weighty earrings on it. You may want to put a bit more hot glue over the string too just in case.
Here it is from the outside.
And there you have your multi-functional earring pyramid :)