So one thing that I do that I would like to spread the word on for people to be more concious about is... I remodeled my house so I have an intimate knowledge of how the plumbing goes when I built my upstairs bathroom. This particular bathroom is the furthest away from the water heater then any place in the house. My shower is turned on by a single lever mixing valve so what I do before I take a shower is I turn on just the hot water to my sink. I wait until that gets hot or warm then turn on my shower. What this does is let the hot water come directly to my shower rather then wasting cold water along with it while waiting to get hot water to my shower. It get the shower ready much faster also.
Obviously people would do this in a regular shower with seperate hot and cold valves, by just turning on the hot first, but if you have just a lever to turn on your shower without being able to control the temperature seperately, this can be useful knowledge to think about how the plumbing is run in your house. Just another thing to be concious of.