It depends what your problem/symptoms are and what your requirements from your shoes are.
Custom shoes/insoles are the expensive ones, they're the ones you get measured up for by an orthotist and they might have cut outs or similar under pressure points etc.
Heel cups/arch supports are the stiff in shoe ones that support those bits and can be good if that is your main problem. Metatarsal domes take pressure off the forefoot, so can be good if it's pain under the ball of your foot that's the problem. I have several patients who swear by fitflops (and love my own) and they offload the front too, so might be an option to try.
You need to see someone who can advise you though, whether that's a podiatrist, orthopaedic clinic, physio or even running shop will depend on your local services and actual problem (eg if it only comes on in your marathon training then start at running shop!)
Physio should also be able to teach you some stretches for your calves and feet to help - rolling a cold bottle under your foot is good for the plantar fascia, and hanging your heels off the bottom stair is great for both calf and sole stretch, lunges too. Strength, stability and flexibility are the mainstays of avoiding operations on feet, so get them moving!