I always float my top and batting. I do a single row of stitching across my backing on top of the batting with the machine locked so that it can't move back and forth, this is my 'start line' for positioning my top. I then pin the top to the back and batting by starting in the middle and going to the outside edge, while pinning I pull the top a little tight before I put in the next pin. Then I pin down the sides, then I put the tension on the sides and start sewing.
I have to much 'stuff' in the way to spray baste....