Ok, here goes:
1) Wear high quality shoes! Those plastic heels from target will never break in, they will never be comfortable, and they will probably break. Good heels usually cost $200-$500 in my experience. But if you want to be comfortable, that's what it costs.
2) Pedicures, pedicures, pedicures. I'm not talking about painting your nails, I'm talking about removing callouses and keeping your feet moisturized. If you have callouses, it may cause the shoes to fit funny and hurt from being worn.
3) Break in new heels slowly. Wear them for a few hours to a movie, then wait a few days and consider wearing them on short errands. Don't go to a party for 6 hours in them until you've worn them several times to break them in.
4) During the break in period, take note of where the pressure on your foot ends up. If your arches hurt, you should put arch inserts in. If your toes keep touching the front and your heels slip out, but the shoes fit when seated, then you need traction under the ball of your foot to keep it from slipping forward and maybe some heel backs to keep the shoes from slipping out the back when you walk. If you slip or fall in your shoes and they have leather bottoms, you may need to have your cobbler affix a rubber sole with more traction to the bottom of your shoe. BTW, I also recommend the foot petals products.
5) If you don't wear heels regularly, start with 3 inchers. Don't jump right into 5 inch heels! Wearing heels builds certain muscles in your legs and you really need to have some ability to wear regular heels before you wear high heels.
That's my advice!