Set out a can or bottle of beer until it has reached room temperature. Dark beers don't work well for this application and the cheaper the beer the better. Leftover beer, if there is such a thing, is fine.
Pour the beer into a clean bucket or container that is large enough to allow a sponge or brush to reach the contents easily. A wider opening makes it easier to keep drips and spills to a minimum.
Stir in Epsom salt. Continue to stir until all of the salt is dissolved.
Add food coloring to add a special holiday twist to this old favorite. You can also make different colored batches to create unique designs.
Cut out or purchase cardboard templates to create snowflakes, snowmen and other holiday figures. Let the children do their own windows if you would like to have more than the classic frosted windows look this Christmas.
Dip the sponge or brush into the mixture and dab or swipe the mixture across the areas of the glass you want to frost. Long sweeping strokes dry to look like windblown frost while dabbing recreates the classic frosted Christmas windows.
Consider using canned frost if you want to speed up the process. Apply canned frost by simply spraying the areas of the window where you want the frost to appear.