I tried everything. These are the three things I'd rank as most helpful.
www.superfeet.com
Active Release Therapy (ART)
www.thesock.com
I wear the superfeet orthotic 24/7, even when orienteering. I would not buy it over the web, go to a running store and test one for fit and feel. A custom made orthotic was not helpful, but I noticed improvement from this almost instantly. I'm up to about 90% of volume now, with no significant pain. The recovery is long; I was diagnosed last October, and my case was mild as these things go.
(I have yet to do speedwork since recovery (this is bad for it), but do plenty of hillwork (also supposedly bad)).
As for ART, I saw a "sports chiropractor" for this. I tend to be a bit skeptical of this sort of thing, but it did seem to help. The theory is that it pushes scar tissue out of the fascia, and blood into it. After a couple months of sessions and careful observation, I was able to perform the procedure on myself, and do so daily. The sports chiro should also be able to address alignment problems; I'm not convinced mine did, but local treatment of the symptoms even if the underlying remains still seemed worth it.
The problem with PF is that everyone's case is different, and what seems to work is often different among people. I just kept trying different stuff I read about. Perhaps it was a case of time heals, but I really thing that there is something to the three things listed above. The injury fora on
runnersworld.com had tons of try this try that for PF, and I found that valuable.
On stretching: I found stretches that streched the foot/fascia seems bad, not good. I found streches that stretched calf muscles to be good. (Note that I'm not referring to a night splint/strassburg sock stretch as bad, I think that one is good). On rolling a frozen can of juice under my foot -- not convinced that this helped me.
I also did exercises where you pick up marbles with your toes, or lay a towel out flat and try to scrunch the whole thing to your foot using only your toes without moving your foot. Possibly helpful.
Good luck with it.