Maybe my method is too simple, but here's my workflow.

Ages ago, I found a simple and free caliper that at 100% scale accurately measures feet. I changed the origin to be the inside of the fixed arm, and I can adjust the height to whatever I want-if I want a character who is 5' 6", I just set the height to 5.5, and then scale the character so he or she matches the height.

As a bonus, I can use it to check the size of various things like cars (the wheelbase is easiest to find and measure) or to see if building are scaled the same as everything else (doorknobs are more or less a standard height, so I measure those.