I'm 6' (or close to it) and weight 210 pounds.
(However, I seem to carry myself and project myself at about 5'10" and 175.)
I think proportion helps -- if your limbs and body (torso, legs, etc) are in proportion with each other, you don't look as big. You want to have a clean profile if you can.
Height coupled with breadth (I wear a 44 bra band) was my largest fear. It still is the only really "bad" spot of my presentation, I worked hard to compensate in every other area that I could actually changed and nailed things.
My secret worst feeling: I hate being in a group of women talking and not being on eye level, I just so badly would love to be face to face without having to sit, slouch, or stoop. Yes, I'm still accepted, and yes, I should be proud of my height, but I still feel closer to the people I'm talking to if I can look straight into their eyes, not down.