Check out this privacy window made with using simple frosted contact paper via Thrifty Fun. Get her tutorial here. She cut the shapes out herself with a pair of scissors but if you have a Silhouette machine this could go so much faster!
Check out these Silhouette Geometric Backgrounds that would work perfectly with this idea! isted from left to right, top to bottom. These would also make great stencils if you were trying to make a large wall stencil.