Your tip is great for in the store
This is what i do after I get it home:
I had plastic templates cut in half-inch increments - 2 through 6 1/2 inches - and taped the outside edges with 1/4 inch masking/quilting tape. That way I could see better the "finished" piece.
I've found not all fabrics cut up equally well in all sizes - especially the I Spy/Novelty type fabrics.