I "break the Frame'"so to speak. Instead of having a contiuious fabric all around , I put a compimentaly fabric in the middle of each border strip( all four sides) , usually the lenght of about three of the blocks or more ( always an odd number of blocks, it just looks more ..intended) . I have also seen in done where the first intended fabric is used on half of the top and half of one side , and then contiuning with other fabrics in the same manner, each fabric only consuming half of two continious sides.