Robbie Daniel (Tornado Olympic campaigner and winner of the recent Alter Cup on I20's) tells me to set the main more by looking at the leech shape than by watching tell tales. With boat on the shore, stand behind the boat on centerline looking up the leech with main sheet in hand. Sheet in until you see the leech of the sail standing up on centerline, then go a bit further. You'll see the leech hook past centerline (to windward). That is too far. Back off the centerline. Get to your normal helming position and view the leech shape. Try to burn this shape into your memory, as it's what you almost always need to achive going to weather. You will need more or less sheet tension to get there depending on wind strenght etc. You cannot just mark the main sheet at what looks like the right position, since the sail will need more sheet or less sheet under different wind strengths. I'm just beginning to use this technique...not sure if I've got it down perfect, but time will tell.
Another gem I picked up from the Charlie Ogletree at the Miami OCR last January...use the downhaul only as a gross adjustment to get enough power to fly the hull and not pop rapidly. Then, with the crew sheeting the main, adjust DH so crew only has to ease/sheet about one fore-arm's length with each puff to maintain the hull out the water. If you're popping up to quickly and needing to dump too much main, put on a little more DH. It takes some practise to have both crew & helsman coordinating/communicating and trusting who is going to respond to each gust, but when we get this technique right, we just scream up wind and the boat suddenly feels like it's on rails. Each puff squirts us forward instead of heeling the boat. Awesome!
Mike.