Step 1: Materials
3. Duct tape!
4. A needle and thread
5. Sock with an ankle long enough to hold an iPhone (thinner fabric is better)
6. A square plastic bag
Step 2: Measuring and Cutting Your Sock
Step 3: Sewing the Sock Together
Basically, after threading the needle, you double the thread back on itself, and tie a knot about a foot away from the needle. Push the needle though both sides of the sock, and then repeat on the same side, about 2 millimeters over. When you get to the other side of the sock, tie another knot to keep the thread from coming undone. I also turned the sock inside out when I was done.
Step 4: Taping the Sock
Cut a piece of duct tape about an inch longer than what would be needed to wrap around the case (horizontally, the short way). With the screen side of the phone up, stick the ond of your strip of duct tape just left of center, and have the edge of the tape lined up or just below the opening of your case. Then wrap it around until it overlaps a little bit. Be careful not to make any folds in the sock.
Wrap two more strips of tape around the case, each should barely overlap the one above it, and the bottom strip should be around a centimeter above end of the case with the seam.
Step 5: Closing the Bottom of the Case
Step 6: Adding the Card Holder
Step 7: Finished!
If you have any ideas to add, please post them in the comments; I'm always trying to improve something I use so often!