I dislike scratched up phones and bulky cases equally, so I created my own shell case that is thin, form fitting, and protects from scratches. This instructable will show you how to use a vacuum former to create a fitted shell case to protect your phone.
Step 1: Tools and materials
For this instructable you will need a vacuum former plus a matching frame, binder clips, a vacuum cleaner, and some source of heat. this can be your kitchen oven, but I use a hot plate. The only materials you need is a small piece of .030" high impact styrene sheet to form the shell from. I purchased mine from USPlastics, but it is also available at hobby stores, etc...
Step 2: Set up the vacuum former
place the cell phone on the vacuum surface placing something about .5" to .75" tall underneath so that the plastic will surround the phone. clip the plastic sheet to the frame using 12 or so binder clips. turn on the hot plate and the vacuum.
Step 3: Vacuum plastic
heat the plastic sheet over the hot plate for 30 seconds to a minute until it is pliable and rubbery. I watch for the plastic to warp and then shrink slightly. once th plastic is uniformly taught over the frame but not smoking, quickly place it on the vacuum surface over the phone. the plastic will be drawn tight around the phone and harden very quickly. I found that using .030" styrene a release agent was not necessary, probably due to the short length of time the hot plastic was in contact with the phone before it cooled. your mileage may vary if you use a different thickness or type of plastic. I tried this on many other plastic and rubber objects I had lying around before I was satisfied it would not stick to my phone.