Shoe bags for travel are a must! They'll keep sandals from rubbing against each other.
Clean and waterproof your suede sandals regularly, and use a suede brush before wearing so they look their best. If they get wet, let them dry naturally.
Always use a cream or paste polish on leather sandals—liquid polish can be drying.
Avoid using chemicals to clean exotic skins. Python becomes soft with use, so no conditioner is required.
Use a silicone-based cleaner to polish patent leather, and use a mild soap to remove any haze.
Clean cloth sandals with a mix of mild detergent and water or baby wipes, and allow them to air dry.
If you live in a walking city, invest in reinforcement for your soles.