I'm not sure that I understand you questions completely, but I think if you are matching top blocks to backing blocks. When I try to match the front to the back at a specific point, I pin baste it first. First, I lay out the quilt sandwich trying to get them lined up at the outside edges and start at one end. I put a needle in the spot on the top quilt, and gently lift/roll the bottom up and push the needle through the spot on the back that I want it to match. I then pin it at that point. I suppose you could tie at that point as well. This works best when the size of the top blocks match the size of the backing quilt. This is time consuming, but you do get the blocks matched up well.