There's a store in my area that specializes in footwear for runners, walkers, hikers, etc. They offer consultation appointments where they figure out the best shoe for a person with how they're on their feet. So many people around here say it's definitely worth the time involved (don't think they charge for the appt, but the shoes they sell aren't cheap so they still make money).
If there's a store around you with a similar service, I'd check into it. Otherwise, good shoes (more than one pair as Dream Baby suggests), good socks, good inserts if needed, epsom salt soaks are helpful (plus it just feels good), elevating your feet when home.
Another idea is to check into shoes made for nurses and chefs; these two professions are on their feet all day long, on hard floors, and shoes made for them provide good support and cushioning.