The first step to producing a sub-zero ambiance is to create mounds of soft, believable snow. Plan the base of your set according to what materials you normally use, and focus on embellishing the surface of your floor. Some animators use baking soda, piling it in deep drifts and sprinkling it over exterior surfaces. Others complain that this method is simply too messy and that the fine consistency of the baking soda is difficult to work with.
Wonderful effects can be achieved by the use of simple sugar or table salt. You can pile them around your set in much the same way as baking soda, but they are heavier and can be manipulated more easily. Salt is especially good to use because it has a bit of a sparkle to it, much like real snow. When sprayed with a fine mist, the outer layer can develop a thin crust, also emulating the characteristics of snow.
If you are working strictly with Claymation, you can achieve a very nice, old-time stop motion feel by the liberal use of cotton. Gather a large quantity of cotton balls and begin tearing and shaping away! Not only can it simulate a snowy groundcover or hilly background drifts, but it can creep and curl from a fireplace chimney and serve as steam that rises from your character’s mug of hot chocolate!
If your scene includes trees, make sure that they are stripped bare of any green foliage. You can paint the branches with a nail gloss or some clear casting resin in order to give them a slippery, icy sheen. This can also be used on any surface of your set that you would like to give a frosty look