I was told a while back to use the following formula to determine which set of tees to play:
5 iron carry distance X 36, for example, say I carry my five iron 175 yards. Multiply by 36 (175 x 36 = 6300). Find a set of tees as close to 6300 as you can on the course you are playing.
NOTE: This method calls for carry distance, not carry and roll!
It seems to work for me. Good Luck!