Place the cottonwood bark carving blank on a work surface. Look over the bark blank and decide how you will carve the house shape based on the shape of the piece and the pattern on the bark. Carve the peak of the roof with the carving knife. Take thin shavings away from the sides of the blank and work your way at carving it until you have achieved the desired peak of the roof.
Carve the sides of the house starting at the ends of the roof on each side. Add whimsy to the house by carving the sides so that they taper from the roof line down to the foundation. Shave off thin slices of the bark until you have successfully shaped the sides of the house.
Add details to the carving such as a door, windows, plants, shrubs and trees in front of the house. Use the small U- and V-gouge chisels to add these details. Carve away thin slices out of the wood with the chisels until you are satisfied with the details. Use the V-gouge to achieve thin lines and textures.
Sand the carving very lightly with a fine-grit sanding pad to remove knife marks where they are unwanted. Sometimes cut marks add detail to the piece, other times they take away from the overall carving. This is a matter of personal preference.
Spray a clear lacquer finish over the carving to seal it. Allow the first coat to dry 4 hours, and apply a second coat. Wait 24 hours before handling the carving.