The number one question I'm asked is "How can you wear heels for so long!?" The answer is combination of practice and picking the right heels (I have heeled boots I can spend a full 9 hours in and others I can only wear for 5 hours or less). But if and when my feet do start to hurt, I switch to flats. 

I think it's helpful to have a flat version of your favorite heels so you can keep the look and opt for comfort. I wore this for a busy day of appointments and work so after my appointments and a few hours at work I switched from my Anne Klein Leopard Calf Hair Heels to my trusty Talbots Tiger Calf Hair Flats. Same look, more comfort!