What you'll need:
-ring blanks with a bezel (I actually got these at Michael's Crafts and they claim to be lead free, so...)
-fabric
-embroidery thread and needle
-Mod Podge Dimensional Magic (in stores now, I believe)
-Mod podge
What to do:
1) Cut a piece of pretty fabric to fit into the bezel cup thingy.
2) Stitch your initial or a design on it with contrasting embroidery thread.
3) Use mod podge to stick the fabric to the bezel. It should fit snuggly and have no wrinkles.
4) Rig something up so you can make your ring stand up and have a flat top. This is important for the next step. You also will need to leave the ring to dry without moving it for a few hours, so be sure it's in a good place out of direct sun and dust.
5) With the application tip of the Dimensional Magic pointing down, fill the bezel. To avoid making bubbles, try to make a continuous stream. Fill to top of bezel so it domes slightly. If there are bubbles, wet your finger and touch it to the bubble. It should pop.
6) After the gluey stuff is dry (a few hours) you may need to apply another thin layer as the stuff sometimes sinks when it dries.