Unless you have an attached garage that represents a prominent feature of your home, you can get away with using a cheap exterior material. Garages aren't typically conditioned spaces, so it's not necessary to use an insulated material as you would for the rest of your home. There are several affordable cladding options for garages.
Fresh Coat of Paint
If your garage's existing exterior is in decent shape, then consider simply repainting it. Prep the surface by cleaning it thoroughly and repairing any damaged areas. Choose the right paint finish depending on the material, and consider applying a coat of primer if you are drastically altering the color. Neutral shades are the most popular for garages, but you can choose a bolder shade for the door.
Salvaged Wood Siding
Visit your local architectural salvage yard and purchase wood siding. You are not only saving this old wood from ending up in a landfill, but you have the opportunity to affordably clad your garage in a material that is preweathered and provides plenty of character. You can stain or paint the wood to make it look fresher, if you prefer.
Sheets of corrugated metal are very budget friendly and can impart a cool, industrial vibe to your garage's exterior. Although it isn't always a suitable cladding material for a home, corrugated metal can be an ideal choice for a garage because it is durable and can withstand dings, plus it doesn't add much weight to the existing structure.
One of the cheapest exterior materials for homes and garages is vinyl siding. It is lightweight and durable, although many people don't find it very attractive. If your garage sits behind your house, though, it might be a viable option. Aside from being cheap, another advantage of vinyl siding is that you never have to paint it and it often comes with extended manufacturers' warranties.