To create a smooth and polished finish on a micromosaic, you need fine grit abrasives and wax.  This kit contains:

Microcrystalline wax - different from paraffin (candle) wax, microcrystalline wax has a fine crystal structure making it to more flexible and malleable but at the same time more dense and tacky.  Heat to melting (using a spoon or ladle) and pour over the micromosaic.  Let the wax re-harden, then polish. 

Silicone carbide sanding disks - these disks are different from more common aluminum oxide sandpaper in part because they can be used in conjunction with water.  Whenever polishing glass, you should also use water in combination with the abrasive.  Put the disk flat on a surface and pour on about a 1/4 teaspoon of water.  These disks are used in order, beginning with the 320 grit disk and moving up to as high at 10000 grit.  The higher the grit, the higher the polish level.

When polishing, take your time and don't skip a grit level.  Start slow and make sure the tesserae are firmly set in the binder.  If you are using Apoxie, you can polish within a few hours of setting the tesserae.  If using micromosaic putty, give the putty time to set, at least a few weeks.