I have been looking for a new suggestion to help us all out, but in looking back through all this stuff I think I should just pick out some important ones.
Time the line. One of the four things to check before each start. Not only will it give you a good idea about how to get to the other end if the wind changes, but a feel for how much distance you go in a certain time and how to position yourself with the rest of the fleet. Sail other little distances and guess how much time and then check it. Dennis Conner was always guessing and checking time and distance.
Try it. Everyone needs better starts.