I'm 5'9, my husband is 5'10 or so...so I usually don't wear them alot, I used to, but the highest I'll go is 3" after that it kills my feet! All you brave women in 5-6 inch heels good lord!! I have _NO_ idea how you do it. I love kitten heels, so comfortable.
Saturday night mine are 3.5"', often stilletto. I always have to tell my husband when we go out-"slow down, I'm in heels." A couple of times I have almost killed myself on our old cobblestone streets and sidewalks. I definitely need more practice.
During the week, it tennis shoes, I am a physical therapist who runs around the clinic all day.
The higher the better.....I only wear flats during the day, but at night nothing lower than 4", 5" preferably....and my highest pair is 6", but they tend not to make it out of the house too often!