Check out the Sailrite videos on YouTube on "30 minute cushions." The Sailrite site has a pattern making app that simplifies things. One of the directions to really follow is the use of basting tape. It is double-sided tape that when sold as basting tape is expensive. When sold as "1/4 inch double-sided craft tape" is one-tenth the cost. You will need several rolls for the V berth. A walking foot sewing machine is still better, but basting tape goes a long way in helping keep the upper and lower fabric even. The pattern is 1/2 inch smaller than the foam, so besure and tack stitch all stress areas (like the zipper ends). Fitting the foam in the finished cover takes almost as long as the sewing.