I recently saw a podiatrist for the first time. My life-long flat feet are causing me other problems now. There is no "cure" for flat feet...I'll never correct it, as may be possible with plantar facitis (which I've also had in the past). But I do have to address the foot support issue or my knees, hips, and back are going to continue to be affected. I got the custom orthotics two months ago and have gradually worked up to wearing them almost all the time. I go barefoot at home for only very short periods.
The podiatrist recommended for walking and exercise only New Balance running shoes...not walking or cross trainers. Running. They have helped and my orthotics fit inside them. I've had to buy other shoes for work. That's been a challenge. No heels. I'm still shopping!