If you are going to STD on the sashing or around the blocks, it is best to do those first before any FMQ. If you FMQ without the straight lines already stitched you are going to get some movement of the quilt top. This is especially important if there are long vertical straight lines because as you look up them from the bottom they can really wander. It's not as noticable for the horizontal staight lines. If I have vertical lines I'm going to do, I pick one in the middle of the quilt and do it first, then I quilt the horizontal lines out from it. I then do my FMQ in the first row on either sides of the center straight line and proceed outward. This is what I do but if any one else has a better method please share it.