I like to buy spiral bound notebooks or journals with gridded lines instead of traditional horizontal ruling for designing quilts and clothing. Barnes and Noble carries one brand in a smaller format, but I've ordered some online with larger pages. I think they're popular in Europe and Japan.
I read an article today about how different kinds of "crafting" are good for the long-term health of the brain, both in developing certain kinds of mental skills and in allowing us to forget the stresses of life, which is just as important. The author talked about the healthy state of being in "the flow", where you are totally focused on creating. For me, the sketching stages of designing a quilt or a new garment puts me in this frame of mind. I need graph paper and sharp pencils to get me there. A computer keypad feels one step removed from the process.