Step 1: The Materials
2 - eye-bolts (I used 5/16" x 4")
2 - 1" x 6' locking tie-downs. I picked up these ones at my local Harbor Freight for $7.99. They are plenty strong and have worked well.
2 - 5' lengths of nylon rope. I was surprised i needed this much for each handle, but it's a nice length. Make sure the cord or rope is rated to hold your weight. This can be purchased by the foot at home improvement stores or good outdoor stores. (REI, etc.)
2 - Handles. I sacrificed an old resistance band. PVC would probably work, but make sure the edges are rounded so they don't cut the cord.