Advice #1 - Copy an Eddy Merckx frame, believe me, he has been obsessed with this subject!

Advice # 2 - You can go to bicyclequarterly.com and purchase the issues that deal with geometry

Advice # 3 - As suggested earlier, you can peruse the internet for geometry of manufactured bikes and attempt test rides at the relevant stores.

Advice # 4 - Ride your friend's bikes, then decide. It worked for me, but that was before clipless pedals.

Bad Advice # 1- You can copy my preference for a sporty bike in the 56-60 cm range, 73 head angle, 5 cm trail, 41.5 cm chainstay, 8 cm BB drop. But what do I know?