A couple basic "rules of thumb" that I use when trying out a new bike; Start with the right frame size, or something close. I'm 5'11" and a 56mm or 58mm frame works for me (I have both), as well as 170 or 172.5 crankarms (I also have both, in addition to a fixie with 165 cranks, but that was originally set up for track use). Set the saddle at mid-height and mid-forward/aft position. Then knees should be slightly bent with pedals at 6:00, sight-line of the handlebar should line up with front axle when riding on the hoods with arms slightly bent. Make adjustments to the saddle height as necessary, but not to the extent that it is at an extreme position. You want to be able to make further adjustments if needed.