The number one way to increase the lifespan of your shoes is to give them a rest between wearings. Try to have at least 2 pairs you can alternate to allow the materials to dry out and return to their original shape after wearing. Protect them from water as much as the materials will allow, and wear socks to prevent odor. Wash fabric shoes in cold water but do not put them in the dryer. If a shoe becomes soaked through, use electric shoe drying inserts to dry them thoroughly before wearing. If you cannot find electric shoe driers, stuff the shoes with newspaper to help draw out moisture and retain their shape as they dry. Replace worn inserts as needed, and look into having the shoes re-soled by a cobbler rather than retiring them.