I agree.........practice on your scraps or an old sheet but NOT on the good fabric until you feel at ease with the rulers and the cutter!! Also, get a lot of those sticky backed sandpaper dots to put all over your rulers so they do not slip on the fabric......nothing worse than a slippy ruler!! I only cut fabric 2 layers at a time....like it lays coming off the bolt. I find it is too easy to get the bends if I start folding and cutting 4 layers.