Fishmeal's Algorithm for Tuning the Rig:
1) Loosen everything, and make sure there are no twists in the wires. 
2) Set headstay length to be slightly longer than the current class 
3) Tighten the uppers until you are afraid something might break, 
   making sure that the masthead is centered (use tape measure from main 
   halyard, wind must be nearly calm). 
4) Tighten lowers to about 2/3 tension of uppers, sighting up sail 
   track to keep mast in column. 
5) Tighten backstay until you are afraid something will break.
6) Adjust aft lowers for desired mast bend.
7) Go sailing. If uppers on leeward side go slack in less than 15 knots
   of wind, they are too loose.
8) Adjust lowers so that mast bends only in vertical plane (check by 
   sighting up sail track). 
9) If you have ever seen a boat of the same size and type with less
   headstay sag, then the backstay is too loose. 
10) Tighten aft lowers if you need a fuller main, loosen if you need 
    a flatter main.