I'm continually amused at what I call "diaper sails" in the BVI. the link added is an EXCELLENT narrative on proper sail trim. I know this is not a "technical" site, but if you don't want to be one of those.... this is really helpful and will enjoy:
https://www.quantumsails.com/resources-a...-headsails.aspx
<img src="http://www.traveltalkonline.com/forums/images/graemlins/dine.gif" alt="" />