I have had great success with June Tailor spray basting. I tried 505 today and it was OK, too. 505 is less stinky, but does not reposition as well when I make mistakes. June Tailor is cheaper and mops up off my floor more easily.
When I spray baste, I use my dining room table. It's very large. I lay out the batting first and then put the backing on top. I seem to get the wrinkles out better that way. Generally, I fold back half of the quilt, spray about a foot or so and them smooth. Spray another foot and smooth.
After I get the backing on, I flip it over and do the top. I'm sure there are many better ways, but this one is working for me right now.