Leather, as durable a fabric as it is, will last that much longer if treated properly. For new leather pieces, apply a waterproofing spray as a preventative measure against staining, and then dry in a cool place. It is very important that leather stays hydrated. To ensure that your leather stays hydrated, condition it with leather lotion - yes that exists - and allow wet leather to air dry instead of applying direct heat. Waterproof, air dry, and lotion your leather approximately every three months for continued results, and never store it in plastic! Rub away a scuff mark with a gum eraser. However, if the mark remains simply mask it with an indelible felt marker or crayon in a matching color. For those salt stains on your boots, wipe them clean with a solution of one cup water and one tablespoon white vinegar.
Suede can, and should, also be lightly coated with waterproofing spray, and sat out in a cool place to dry. As is also the case with leather, this is most effective when the item is new. Grease stains (the kryptonite of almost every fabric) on suede can be treated by carefully applying a sparing amount of dry cleaning solvent mixed with an absorbent, like sawdust. Be sure to test the mixture first on a tiny concealable area to prove that it won't damage or remove the color of the suede. Use a suede brush to dust away any dry stains like dried mud, or to revive any dull areas. Salt stains on suede boots can be remedied with the same water and white vinegar solution mentioned for leather above. Dry clean your suede apparel to remove overall dirt accumulated from wear.
Velvet, like suede, should be dry cleaned, unless the item's tag advises otherwise. Though, velvet, unlike suede, won't incur as many injuries, and thus has less at-home care instructions. The only thing your velvet asks of you, other than a trip to the cleaners, is to refrain from ironing it at all. Ironing velvet will crush the fibers, and leave a permanent to semi-permanent imprint. To remove creases and wrinkles, steam the piece lightly while turned inside out. And once you're ready to store your velvet again, avoid folding it sharply or using any methods that will flatten the fibers. If hanging is possible, that would be best. If not, stuff the piece with tissue paper to minimize the creasing or flattening of any portions of it.
Truthfully, clothing is an investment, period. Regardless of how much or how little an item costs. And it makes sense to protect every investment so that you can enjoy them for years to come. Using the tips and tricks above will help preserve your fall and winter pieces in these fabrics while they protect you from just about everything.