I had plantar fasciitis a few years ago - hadn't a clue what was making walking so painful/impossible, before self-diagnosing courtesy of Google. Bought some supportive Scholl insoles, around £25 in Boots, wore them for a few weeks, magic.
Subsequently 'diagnosed' the same in a BiL, who was complaining of similar, which was confirmed by whichever doctor he saw.
He spent 100s of ££ on specially made insoles, which unsurprisingly did the trick, too.
BTW, isn't plantar fasciitis what used to be called fallen arches? Or have I got that wrong?
My feet aren't too bad, except that one has always been wider than the other. I have a lot of trouble finding comfortable shoes, esp. since I don't feel ready for the really old-lady ones yet. And like a pp, no wearing in - I've wasted a few pairs like that. If they're not comfortable immediately, I don't buy them.
I have a microplane thing for hard skin, works fine, and I do my own pedicures, since I hate anyone touching my feet. I soak them in a bowl of warm soapy water first, usually in front of the TV!