I have seen people say 1/4, 3/8, and 1/2 inch. Which thickness do you use for your cookie dough? If I knew how to do the poll, I would do that. Since I don't know, I am hoping that some of you will be kind enough to share. I am making my first batch of cookies this week and will likely experiment at that time. I printed out the instructions on how to make and decorate your cookies. Thanks!
Here's another thread on thsi topic with some good info: http://cakecentral.com/cake-decorating-ftopict-618235-handle.html
I roll 1/4" for regular sized cookies, and a little thinner for anything really small (like, under 1" wide).