I have a longarm and I only have the backing attached to the take up and belly bars. I have a velcro leader..I take it off..and on my sewing machine...I do a long running stitch..attaching the backing to the leaders. I then velcro it in place. Then a few inches down..I float the top and batting...basting it with a long running stitch. I use quilt basting spray between the layers. This makes it easy to smooth out..it holds it in place. I use side leaders on all three layers. Check out Sharon Schambers website..she has some great videos about the subject. She has a free pattern for side leaders that are of canvas with a dowl rod that is a lot better (I think) then just clamps. It is hard to go into great detail on here. I did my first quilt on my longarm using all the bars and I thought I would go nuts. I have done 5 king size quilts using Sharon's method and am taking about an hour to mount the quilt. I hope you check her out.