Our house is entirely electric, no gas or oil, so the electric bill can get expensive.
We learned that one of the biggest electric hogs in the house was the water heater. So, we put it on a timer. We only have it on in the evenings from 5 to 11. That's the time of heaviest water usage with cooking, laundry, showers all happening during that time.
And believe it or not, it keeps the water in the tank hot from 11pm until 5pm the next day. So it's only on for a quarter of the day. It still gives you enough hot water for one load of laundry or a shower without depleting the supply.
If I'm home doing lots of laundry and running the dishwasher at an earlier time, I just manually override it and turn it on.
Also, we set the temperature down at 120°F. It will still give you a hot enough shower, but it's below the threshold for scalding burns. Important when you have small children.