I got the latest copy of Bowhunter magazine last night. There is a very interesting article in there about rattling. To sum it up, most hunters don't rattle loud enough or long enough. Mornings are best, overcast days are good, pre-rut, rut, post rut all work. Pick up a copy and give it a read.
I did some light rattling this past weekend. I wish I had done more and will likely have the rack with me this coming weekend.