I spray baste for the most part. I generally toss in a few safety pins near the edges.
As far as people worrying about the spray basting being a chemical, I figure by the time it's washed a couple of times there won't be any more chemical from that than all the other stuff used in the manufacturing process.
I HATE to pin baste an entire quilt. I can't seem to use a closer tool properly and end up wearing all the skin off my fingers. While quilting, removing pins is a bother, too.