Paint the background in Spa Blue and Snow White. Cut out the provided circle template to a desired size. (This one is about 10" wide.) Tape onto the center of the wooden sign and lightly trace in pencil. Sketch out the hills based on what shows in the circle area. Cut out with a craft knife. Lightly trace the shape of the hills onto the wooden background.
Transfer the mountains using transfer paper. Paint in the mountains using various purples, making the tops of the mountains slightly lighter than the bases. Let dry. Once dry, paint a jagged snowcap for each mountain in white. (Be sure to paint slightly below the hill line.)
Transfer the provided house and tree patterns onto watercolor paper. Paint the trees and house in various shades of blue. (See photo.) Let dry. Once dry, cut out with a craft knife.
Paint small footsteps with a round brush in a mix of white and Calypso Blue. Use Glue Dots to adhere the house and trees onto the hills. If desired, paint the wooden frame (already attached to the sign) in Ultra Deep Blue or another dark blue. (This will be washed out by the frosted window.)
Place the plexiglass on top of the wooden background. Align the circle template with the penciled circle on the background. Tape into place on the plexiglass. Wet a sea sponge and wring out the water so that it is damp. Use Cotton Ball to sponge on the frost, overlapping the circle cut-out.
Adhere the plexiglass (paint side down) onto the wooden surface with E6000 Glue. Allow to dry completely with objects placed over the surface so it remains flat.