At my last apartment, I didn't have to pay for water, hot or otherwise. This caused me to become complacent. While I never ran the dishwasher unless it was full, I took long showers sometimes and occasionally left the water running when I brushed my teeth. In the new house, I'm trying to reel all that in. Here's some of the stuff I've done so far:
1) I fill a little glass with water to rinse after brushing my teeth instead of inefficiently scooping water from the tap like I usually do.
2) I only shower every other day, and turn the water off when I shave or shampoo my hair. (Note: this was not as cold or horrible as I expected this morning and I'm the woman who keeps the heat at 54 degrees!)
3) Anytime I need to wait for the water to heat up at the sink, I put the cold water in a container and use it to water the plants. (Lately I've been using these big beer bottles from our last homemade batch; foder for another post.)
4) I'm saving pasta water for the same reason, though I'm uncertain if the starch is at all harmful to the plants and need to do a bit more research on that.