Of all the tools in your shed, the electric hand drill is probably the one that gets the most use. Since it's regularly overworked, replacing or at least sharpening an electric drill's bits is crucial. Power sanders are another popular power tool. Since they collect dust rather quickly, it's a good idea to clean out the dust from this machine's air openings on a regular basis. You can do this by using compressed air, a brush, or simply by blowing on the dusty areas.
If you get a lot of use out of your drill press, the main thing to look for is accumulation of rust. You can help prevent rust from setting in by wiping down all metal areas and the table with either oil or paste wax. One machine that tends to grind down due to misuse is the saber saw. Simple steps, including having the blade shaft assembly serviced once a year and adjusting the speed of the machine based on the material you're working with, can add years to the life of your saber saw. Your hedge trimmer will work better if you wipe down its blades before every use. That string trimmer of yours will also work better and longer if you clean its deflector prior to using it. The chain saw is a tool that's particularly helpful for such major tasks as chopping logs or felling trees. This tool will benefit by you keeping important areas, such as the fuel cap vent and paper air filter, clean.
Regular care will also keep your lawnmower running for a lifetime. You'll want to check your mower's oil levels on a regular basis. Garden tillers and snow blowers are two other common household tools that will last for many years if you simply keep their component parts clean and get them serviced regularly.