Hi,
I haven't tried this yet (and may never do so!), but I got this advice from Shauna Hullender, who made these beautiful glassy beads:
http://www.etsy.com/listing/54769220/6-green-blue-yellow-stripes-handmade"I use wet dry sand paper from the automotive store. I use three different grits, 400, 600, 1000. Some people say to use more but this works for me. Start with 400 and go to 600 then 1000. Get a bowl of water and tear some pieces of sandpaper and lightly sand every surface, be sure to keep your bead pretty wet. go thru each grit this way. then buff your bead with a soft cloth. You want to check for any scratches or rough spots. If done wel,l it will feel like glass when you are finished. Then I use Future floor polish. Get a soft paint brush. I put on three coats, letting them dry 30 min in between coats."
I have tried Future floor polish and it really does accentuate the glassy quality of translucent clay.
Also, I have seen several references to Premo "Frost" being the most clear of all the translucent clays.
Good luck!