If I develop plantar fasciitis, how will it be treated?

Combo treatment.. If you have plantar fasciitis, and hurt most with the first few steps in the morning, the more you can do together, the better: #1: supportive shoes. #2: firm inserts or orthotics. #3: oral antiinflammatories (check with your doctor). #4: stretching your foot and calf. #5: icing (10 min at a time). You may also need physical therapy or cortisone injections, or eswt if available in your area.
Multiple treatments. Plantar fascitis is complex condition that can be treated with simple stretching but in severe cases may require surgery. Typical treatments include: home stretching, nightsplints, orthotics, cortisone injections, physical therapy, shockwave treatment (eswt), and on rare cases plantar fasciotomy (partial release of the plantar fascia ligament).
Stretching. Usually it will be treated with stretching exercises and nsaids depending on your response, you might require a local cortisone injection, physical therapy or shoe inserts.
Protocol... I'd say 98% of my plantar fascitis patients respond to non-surgical treatments... Rest, supportive insoles, rx orthotics, otc anti-inflammatories (like aleve), prescription nsaid's, steroid injections, prp injections, physical therapy, etc... If all else fails... Surgery.