This is a simple duct tape cover for a "candy bar" style phone, like my Motorola L6 SLVR.
It has a liner to keep the phone from getting scummy from the adhesives in the duct tape and a flap on the back to protect the lens of the integrated camera.
Step 1: List of materials.
2. Scotch Tape
4. Although it's not in the picture, a ruler. Not so much for measurements, but to help tuck the tape inside the case. (You'll see what I mean later.)
5. Lining material. I used the thin sheet packing foam that came in the box with a keyboard we ordered at work. You could use anything that won't scratch your phone. (Plastic bag, Tyvek envelope, etc)
6. Phone, to use as a template.