there are several techniques to accomplishing the end goal of borders on qayg...i personally design my quilts to include borders into my blocks before putting my rows together with sashing strips. i always use a slightly larger backing block and batting block when quilting then trim down/square up before doing sashings. if you plan out your design and patterns on graph paper before making first cut of fabric and first stitch then you will know exactly where the blocks with borders go and also have a quick reference guide when finally putting it all together.