Connie,
Not to move in on Karen's beautiful creation, but when I make baby quilts, I try to make them about the size of the batting, but lately I have been sticking with about 1- 11/2 yards because it is so easy to know the dimensions that way and figure out blocks, quarter triangles, etc. Crib batting is usually 45x60, but I bought cotton batting crib size and it was 48x60. I must say that baby quilts have been the only cotton battings I have soaked so they don't shrink or pucker. And it has worked well. I almost have the teddy bear toille done! :D