I had tremendous success with the
Superfeet OTC orthotic. Custom and other OTC orthotics did not help.
Other things that I think helped were the Strassburg Sock and ART. The SS made my leg numb, tho, so I stopped wearing it. ART is something I learned to treat myself with after a few sessions of observation (especially if insurance is less than generous in paying); the theory seems quite simple -- squeeze scar tissue/ossification out, squeeze blood/nutrients in, at least it seemed to help me; the new age music and other trappings seemed less medically useful. (Disclaimer -- not medical advice, consult your medical provider before treating yourself :-))
But definately try the Superfeet. I had quite a long and annoying battle with PF, and they just seemed to work, and pretty quickly. Now I wear them pretty much 24/7, with no relapse. Fits in O shoes and running shoes also. Note that PF cures are different for everyone, so YMMV.