Place your pendant on the front of your frame. Make sure the frame extends farther out than the cab. Use a small amount of painter's tape or quilter's tape to secure the cab to the frame.
Starting on either side of the pendant, grab two of the bail wire ends and bring them from the back to the front. I find it easiest to hold the cab firmly against the frame with my thumb and index finger.
This next part may test your patience, so take your time.
Begin forming small spirals, one inside the other, to create prongs that will hold the stone. Trim the wires shorter to make them easier to work with, and make small, controlled movements as you shape them.
You can adjust the spirals slightly as you go, but avoid creating sharp bends.
Use round nose pliers or your fingers to form the spirals that will sit along the sides on the front of your frame. Trim any excess wire once you have the spirals shaped the way you want.