For major repairs and home upgrades, you may be able to get a better deal if you shop for materials like tile, air conditioners or lumber separately at a discount store or warehouse rather than paying the markup many installers tack on to materials they provide, according to "The Owner-Builder Book" by Mark and Elaine Smith.

Just make sure you work the deal out with the tradesman or contractor beforehand and find out any technical requirements he might have for materials before you buy.

Another good way to save money for skilled DIYers is doing the less-complicated-but-labor-intensive first steps of a home-improvement project and calling in a professional to finish it. For instance, if you're doing a bathroom remodeling job, you can yank outdated mirrors, flooring and fixtures yourself, but call in professionals to do the plumbing and remodeling.