Hi!
I asked my doctor about this, and he said you should do a couple of things - like the previous poster said, wear sandals, but the arch support isn't as important as elevating your heal - notice when you have plantar f., walking bearfoot makes it hurt more? If you wear shoes with an elevated heal (like sandals with a small heal) it doesn't stretch that part of the heel as much. Definitely do this in the morning (when plantar f. tends to be the most noticed)
Also, like the previous poster, massage your heal. Sit on the edge of a couch, take your foot in your two hands and pull your toes toward your knee (like when you do a Cathe calve stretch). Mash on the soft part at the back of your heal, under that bone that sticks out at the back of your heal. I was told to do this several times a day.
Also, its possible you have what's called bruised heel syndrome. My doctor went to a conference about sports injuries and learned of this syndrome, which seems similar to plantar faciitis in some ways but isn't as bad (check it out with your doctor).
I'm a bad example, because I kept exercising with p.f. and it didn't get worse - had episodes where it was better and worse. My understanding is this is how it works - you'll always have an affinity for it, but it will come and go.