Fresh water savings

The first thing I did was to move the vent location on the tank from the side to the top. Where it was located reduced our water capacity by at least 10 gallons by trapping an airbubble at the top of the tank. Our coach has a pressure water fill system and didn't have the ability to dump water from a container in to the tank. I added a gravity fill system on the other side of the coach so we can now fill from either side. This comes in real handy while we're dry camping at the beach and have to use jugs or water coolers to fill the water. In recent years we've never run out of water on our trips but it's nice to know it's there.
I ran the vent pipe to the roof through a dishwasher air-gap and back down to the bottom of the coach. This keeps water (on a full tank) from pouring out the vent while on hills or going around corners. You'd be surprised how much a tank can drain while on a hill. I've been told the vent line can be tied in a knot to mitigate this but our system works better. I don't use the vent fitting on our gravity feed system, just one vent for the tank is all you need.
I also installed a 15 minute switch in line with the water pump switch so there is a greatly reduced chance of the pump running all our our water out through a broken pipe late at night. I've seen it while camping. It's a nighmare for those it happens to and those next to them.
We have a commercial push style faucet in the bathroom which I set to an absolute minimum on time. This really helps when washing hands or brushing teeth (especially with kids).
Also, we have a cup next to the sink and we're all trained to catch any extra water running from the faucet. It gets saved for the next person to use.
I installed a shutoff valve for the shower. It works better than the shutoff the coach came with. This saves a lot. My wife catches the cold water in a bucket while waiting for the warm water to hit. We use this for our feet cleaning bucket at the door for the next day. 90% of our camping is at the beach and we have a lot of sand to deal with.
I've been toying with the idea of a temperature regulated shower valve to save on that warm-up water savings but haven't gotten around to it yet.
My cousin says we make our 60 gallon tank look like a hundred or more.