I want to try a machine flanged binding soon, but have not been impressed with machine binding up to this point. So I attach to the top and hand stitch to the back side much like Tartan explained. One of the things that has really helped me is to switch to a poly thread that doesn't tangle or shred like the all cotton seemed to do. And from your description of the stitch/hump I'm wondering if your bindings are "thin" or not filled with bat/materials. I make sure when I'm trimming the quilt in prep for binding that I leave about 1/8" of bat overhanging where I plan to place the binding edge for sewing with my 1/4" seam. That way, when I roll the binding to the back there's a little bat to fill the binding roll. This seems to make the whole binding much smoother. If I cut a little to close, I'll tuck in a short string of bat as I bind that spot. I use those snap hair clips to hold the binding folded over and it makes the binding lay flat when I'm sewing.