I made my sails for my schooner. The sail making took as long to make as building the boat, and it was a learning experience from the onset. I wanted canvas sails, not Dacron, since the boat was of a old schooner design. I found that the canvas needed to be preshrunk, seamed every 8 to 10 inches to prevent stretch and add strength, to have a rope stitched around the edge of the sail, that stress points had to be reinforced, that the grommets put should be crimped in then also stitched in, and last that much of this had to be done by hand.
The schooner has just under 200 sq. feet of sail when all three sails are up. I got very good at sticking myself, and that blood comes out of canvas with cold water if soaked right a way. I also figured out why Rum was popular. One tool I made, and was suggested by an old sail maker was a sail-makers bench. I copied his. It made a major difference and made the job much easier. You could sit on the bench off the floor and have the sail so you could work with it. The photo shows the bench. You ride the bench like a horse with the sail on your lap and the tool rack keeps tools from getting lost in the sail. Keeping the cats from the sail was another matter altogether.