The more you learn what works for your type of boat, and your rigging, and wind, and crew weight, and sail shape, and waves and skills, the more fine tuning comes into play.

I would talk with others who own the same boat for general advice, crew for them as often as you can... read all you can get your hands on, but most of all sail EVERY day... and that should be a good start to understand all the different fine tunings.... (hehe... kidding, kind of)

I have been sailing for over 30 years... cats for 10... and have sailed seriously for the past 3 years (over 100 days a year). I feel i am JUST getting to understand fine tuning, apparent wind, vmg and the biggest lesson i EVER learned.... NEVER, EVER, EVER pop the chute with my girlfriend onboard.... hehe... the 2 just dont work well together.