Most layups require that a second and third ply be positioned precisely over the previous ply. Unfortunately, large plies of cloth will easily distort when handled, especially BID. The plans recommend rolling them up, then unrolling them onto to the previous ply. But that, too, will distort its shape. And once a ply starts to wet out, the ply becomes more and more troublesome to move. The fibers become harder and harder to orient and straighten. The builder ends up with a distorted ply that eventually gets peeled up and tossed in the trash can.
Here's a technique I use to precisely position plies without distortion.
Place the next ply onto a sheet of left-over masonite, formica, poster board, or a piece of cardboard from a large box. A semi-rigid sheet of anything will work as long as it has a smooth surface. Orient the cloth into the proper shape, making sure to check the dimensions along the edges and to straighten all fibers. Leave about 2-3 inches of cloth overhanging one edge of the board.
When ready, pick up the board and "hover" over the previous ply. Allow the overhanging edge to come into contact with the previous ply. Wait a few seconds for the overhanging cloth to soak up some of the epoxy and "stick" to the previous ply. Tilt the board upward just a bit and gently, slowly pull the board out from under the ply. With the ply "stuck" to the previous ply, the cloth will slide off the board and drape perfectly into position over the previous ply without getting distorted out of shape.