You need energy to heat water. Therefore, if you can get clean without using so much hot water, you'll save. But which uses more hot water, a bath or a shower? This experiment will help you determine that.
Ask everybody in your household to take a bath instead of a shower when they need to wash. Make sure each person leaves the water in the tub when he or she is finished. Then check the height of the water. You can mark it with a bath crayon or with colored tape. Or you can measure it with a ruler and record the level.
Next, have everybody take a shower. (This works best if you have a shower/tub combo.) Ask them to plug the drain before they start so the water doesn't run out. Measure the amount of water left in the tub when each person is finished and mark or record it.
Now compare the average amount of water used for each method. The one that required less water is the one that will save more energy -- and the one you should recommend for use in your household.
Think of ways you could save even more energy. What if you turned off the shower when you're soaping? Using a low-flow shower head, which can put out as much as 72 percent less water, can make a difference, too [sources: Energy Information Administration: Saving, titanheater.com].