id start with a baseline height using one of the popular formulas. i use the lemond formula (inseam x .883) to determine initial seat height (distance from top of seat to middle of bottom bracket). get that set first then do the fore/aft set up. feel pressure in front of your knees? move the seat back. feel like you are sitting on the narrow end of a 2 x 4? move the seat forward. make sure seat is level always. tah dah....