I have plantar fascitis and this is what my podiatrist has told me to do.
Roll the arches of your feet over a frozen water bottle. It works great! It reduces the inflammation of your tendons in the arch of your foot, which is what causes the pain in your heels.
He also suggests that I take 1000mg of Motrin everyday, but I would check with your own doctor before doing that.
It works, and it's the best relief that I have found.