I recently bought 3 yards of 60 inch wide “Sunbrella” fabric for about $60. I was able to make both a main sail and jib cover with enough left over for a tiller cover.
For the main sail cover I cut the fabric 34 inches wide along the 9 foot length and zigzagged the edges to keep it from raveling. I pull my Capri 14.2 up onto a dock when I am not sailing it. I hold the boom up with a mast holder that fits into the rudder grunions. I flake the main sail around the boom and tie it with sail ties. I then put the sail cover over the boom and secure it with 5 bungee cords.
My jib is roller furling. I cut the remaining fabric into two pieces 13 inches by 9 feet long. I then sewed the pieces together and cut a 14 foot long by 13 inch wide piece. After zigzagging the edges, I ironed on half inch wide Velcro on both sides of the full 14 foot length. I then sewed a one inch loop of fabric to one end of the fabric. I tie the main halyard to the loop and close the Velcro as I pull the jib cover up over the jib.