I've always been a runner, and got it many years ago. In my experience, the best solution, by far, is wearing quality shoes that have good arch support. Custom orthotics are great, but not necessary if you ALWAYS have good shoes on your feet that have good arch support. Custom orthotics do help a lot, especially if you don't have good shoes.
These made in China shoes and sneakers usually have terrible/flat footbeds. I wear made in USA Ethan Allen shoes, made in USA boots (H&H, Justin, Chippewa, etc., but the made in USA models make a difference), and have found Brooks running shoes to have good arch support. Nikes are terrible.
To "fix" the problem, get a pair of Halfingers. These are German (might be made some other Eastern Euro country now…) slippers/moccasins. They have a great arch to them and cork footbed that conforms to your foot. Expensive but well worth it.
The secret is to slip them on before your feet hit the floor in the morning. Without doing this, your bare foot stretches flat, re-aggravating/tearing the fascia tissue. Putting your foot in the Halfinger slippers first keeps your arch in the curved shape and allows for continued healing. Wearing the Halfingers around the house keeps your foot in good shape, as does wearing quality shoes. Throw out the junk shoes!
As for exercises that help, the best thing I've found is to stand on a hardwood step, barefooted, with just the front part (ball of your foot) on the step. Slowly (slowly) dip down a little, then go back up to parallel, and do some more reps, this stretches the fascia. Also, roll a tennis ball, or better, a Lacrosse ball under the arch, with some body weight on it.
Hopes this helps. Once "healed" Plantar Fasciitis can very easily be revived. I've been good for years now, but until I adjusted my shoes, and was consistent with how I got out of bed every day, it would come back. It's an ongoing thing that I need to pay attention to.
Good luck.
