Waterproof spray is your friend. Spray your leather, suede, and canvas shoes before you break them out!
Beeswax makes a great natural waterproof-er for your canvas shoes. Rub a layer over the entire canvas surface before setting it with a blow-dryer.
Wave goodbye to those water marks and salt stains on your prized leather boots. Mix a few drops of vinegar into a bowl of cold water and scrub the solution into the leather with a soft bristle brush. Otherwise, wipe down with water and half a squeezed lemon. Leave the boots to dry overnight.
Besides washing, waterproofing, and polishing, you should semi-regularly CONDITION your leather boots. This literally adds years onto their lifespan. Think of the beating your leather takes against the water, salt, dirt, and grime of wintertime. As skin without the regular nourishment provided from a living body, leather will dry and eventually crack when it loses its natural oils and moisture. Leather conditioners prevent this breakdown, so don't hesitate to lather up!
For a creative and cheap way to clean dirt off your delicate suede beauties, let a bread crust go stale, then gently rub stains with said crust until they disappear.