Just about anything bad that can happen to a sail falls under one of these categories. Following are some specifics on making sails last longer, and avoiding the things that shorten their lives. Check the sails regularly. This may mean once a year, if everything seems normal, or more often if you've had an 'event'. Look for areas of chafe.
Seams are one one of the first places to check.
Worn seams should be re-sewn and you should consider extra protection for areas of obvious, repeated chafe. Once the sail is chafed or torn, it's usually pretty easy to go back and find out what did it, but it makes more sense to round or pad edges first. Have your sailmaker place chafe patches on the sail where spreaders, stanchions, and anything else might rub frequently. Even smooth objects can wear a sail over time. Environmental effects 1.