I spray baste my quilts, then usually do a couple of rows each direction with water soluble thread before I quilt. That holds it in place so I can start anywhere. I generally start at the edge in the middle of one of the sides and work my way to the other side. Then I do the same to the right and left of that until it's done. Larger quilts I tend to do as much in the middle first to get it over with because it's harder to reach.
I usually have an inner and out border and generally stitch in the ditch around the borders and stipple the center of the quilt and the outer border. I've ignored the inner border and just stippled, but I don't like it as much that way.