What Racquel said. I'm not usually that good in heels, but I have a pair of 4" killer heels, (which were originally bought not to leave the bedroom) and they are SO comfortable. They are just right for my feet I think as when my SO wears them (we have the same size) he claims they're nice but he couldn't wear them for as long and he manages heels better than I do
Practice wearing them and consider getting those gel insert thingies so it's not too hard on the balls or your feet.