Last night Jill Schumacher
http://www.quiltmakertothequeen.com/
spoke at our guild. She pin bastes and said to put the pins in, starting in the center but do not close the pins until all are in. Closing them while pinning will put wrinkles on the back. I had not known that.
Jill attaches the backing to a table, taping or clamping it, "floats" the batting onto it, "floats" the top onto it, smooths it out then starts in the middle to pin. She even showed us how you can use a 3 foot wide table. Just start with the center of the quilt on the table with the rest draping down. Pin, pin, pin, then shift the whole thing and pin, pin, pin. It looks quite do-able! I hope I have made this clear.
JoAnne