I spray baste with June Tailors spray. I work on my deck, putting down a large sheet, lay the backing down and then the batting. Smooth it all down and then fold back the batting at the middle. With my shoes off, I walk up to the end and on the batting I folded back and spray that half of the batting. Then pick up the batting and start walking forward until I get it back where it should go. then do the other end and the top the same way.
Don't have to get on hand and knees much that way.