Mix a tiny amount of fine, iridescent glitter with Snow Flake Snow™ until the desired look is achieved, keeping in mind that a little goes a long way. Spray an already modeled snow base with Scenic Cement™ and apply the mixture while glue is wet.
You can also mix glitter with Water Effects™ before modeling icicles.
Prepare your water areas as usual and pour Realistic Water. While it is still wet, lightly sprinkle Soft Flake Snow on top. This will create a glazed, frosted look to simulate a frozen, icy surface.