Your refrigerator will stay colder, run better, and last longer if the cold air can circulate easily. So don't overstuff it with food. Do the doors seal properly and keep the chill in? Close the door on a slip of paper and tug on it. If it slides out, it's time to replace the gasket so that your fridge doesn't work as hard. Compressor coils clogged with dust can't release heat efficiently and make the fridge work harder, wearing it down. Cleaning the coil with a brush and vacuum once each year will add years to the life of your refrigerator.
Your dishwasher will last longer if you clean the gasket routinely with soap and water, and take the time to remove food debris regularly from the filter. Much of the energy used by your dishwasher goes toward heating the water. So before you do a load, run the water at the sink until it gets hot. That saves the dishwasher work, and it will last longer.
Keep your range working its best by keeping the burner ports clear using a pipe cleaner or paper clip.
Don't overwork your dryer. Clean the lint filter before every use. Use the Auto Dry setting—that's going to save energy and wear and tear on your clothes. And clear the vent annually to help the dryer run efficiently and help prevent a fire hazard.
Overstuffing your washing machine strains the motor, transmission, and other parts. You can fill it, but loosely. Your laundry will come out cleaner and your machine will last longer.
As for your vacuum cleaner, change the bag frequently and keep the filters clean. Check the brush rolls before you start to vacuum to remove pet hair or long fibers. And if you have a retractable cord, don't let it reel in too fast. That will keep the plug from breaking off.