Add only as much water as necessary for cooking.
The more water you use, the longer it will take to heat. On the other hand, adding less water will allow you to use lower temperatures and shorten cooking times.

Choose pots and pans that fit the size of cooktop burners.
A 6-inch pot on an 8-inch burner loses about 40 percent of the burner’s heat to the surrounding air. Conversely, oversized pots and pans won’t heat efficiently, extending cooking times.

Downsize cookware whenever possible.
Use the smallest pot, pan or baking dish for the portion you’re cooking.

Use flat-bottom cookware.
For the greatest heat transfer from an electric cooktop cookware should rest flat on coil-style, solid, ceramic, halogen and induction elements.

Put lids on your pots and pans.
Lids help retain heat, allowing foods to cook faster and more efficiently. Your kitchen will stay cooler too.

Keep gas burners clean and adjusted.
A blue flame means proper combustion, but a yellow flame indicates service is needed to ensure that the gas is burning efficiently.

Wipe off the cooktop.
Baked-on spills can inhibit the heating of the burners, as well as reduce their lifespan. Also polish dirty burner pans under the burners so they reflect the heat, rather than absorb it.

Limit oven preheating.
Unless your oven automatically handles the preheating function, restrict preheating time to a maximum of 10 minutes.

Covering oven racks with foil is a no-no.
An oven works most efficiently when air can circulate within it. Stagger multiple pans to maximize air circulation too.

Check the oven with a thermometer.
Also monitor whatever you’re cooking with the appropriate thermometer to make sure your oven’s controls aren’t wasting energy.

Watch cooking progress through the oven window.
Every time you open the oven door, the interior cooking temperature goes down by 25 to 30 degrees.

Make multiple meals in the oven. 
It takes less energy to reheat meals than it does to cook them.

Use the microwave, instead of the oven.
You’ll save up to 80 percent on energy costs and decrease the heat load in the kitchen too.

Cook or reheat small portions in a specialty appliance.
Lower energy consumption by using a toaster oven, mini-grill, pressure cooker, steamer or slow cooker. You’ll reduce heat in the kitchen, too, which helps cut air-conditioning costs.

Inspect the oven door gasket.
If you find burned, crushed or damaged spots, replace the gasket to prevent heated air from escaping into the kitchen.

Adapted from “Major Home Appliances” published by Iowa Energy Center (http://www.energy.iastate.edu)