This is my version the Lens of Truth as seen in both Legend of Zelda games Majora's Mask and Ocarina of Time.
Step 1: Start
I started with a 5" magnifying glass I purchased off of amazon for 10 bucks.
Step 2: Handle
The handle was made out of a piece of poplar wood turned down to my desired shape. Then I drilled a hole the size of the magnifying glass shaft, and slipped it over aforementioned shaft.
Step 3: Lens
The magnifying glass as it comes is flat, so to give it some volume as it looks in the games I added some epoxy putty to the rim. After hand smoothing as much as possible I sanded until I reached the desired smoothness.
Step 4: Horns
The horns were made from cast plastic. The gem part was cast from a store bought gem from a wedding gem pack. It was then cast in Smooth-cast 325 with red So-strong pigment to give it the ruby look. The pieces that the gems rest on was a turned piece that I cast to get multiples. For both molds I used Smooth-on Mold Star 16 Fast.
Step 5: Eye
The eye was as simple as printing off the shape in red on photo paper. At some point I might go back and make a cast piece, but the paper works for me.
Step 6: Paint
For painting I used an airbrush for the many components then hand painted the lens. I used an iridescent purple airbrush paint that I mixed myself to get the right color. Then washed over everything with a coat of black. I did use a spray can to get the gold pieces painted the right color.