My best investment was "Quilt in a day" Triangle Square Up ruler, that along with a tip from the Rotary Magic book by Nancy Johnson-Srebro, my quilting bible :thumbup: Never bother with the 4 3/8" measurement, she recommends measure up and trim down, so 4 3/8ths would become 4.5" it really works for me.
As for those "design changed" HSTs put them in a box to use up in scrappy quilts, saves on frustration and grey hairs :mrgreen: