I, too, use just any old thread. Usually I pin baste but on a large quilt it can add to the weight that you are wrestling with either hand or machine quilting so thread basting has that value for me. I also agree that you don't need short lengths of thread for this process. In fact I had read/heard/seen somewhere (and it worked for me) was to place the spool in the center of your quilt, thread one end and baste to the edge. When you get that side finished, pull enough thread to go to the other edge, thus you get a single thread from edge to edge each time. I also thread baste about the same distance as pin basting - about a hand-width apart. I hand quilt so that works for me - not sure how that would work for the machine quilters.