Stick to your word. Do what you agree to do.
Use a fixed hose reel, it's a simple case of open the door grabbing and going. If you can, try to mount the hose reel shoulder hight..no bending or yanking needed.
Keep your van clean at least on the outside by washing over with the wfp at the end of the day
It's already been said don't treat your customers like mates..always sir/mrs/ms be friendly, don't try to solve every problem they come to you with or you will end up an odd job man. Remember you can have a good rapport with your customers without having to be chatting for ages, your relationship stops with the £. Who was it who said "No doshy No washy" it's always stuck with me that.
Get on and do the Job.
Be polite and smile, even if someone is rude to you or messes you about. You just don't know who they may know, and even if they are in the wrong and you tell them what you think of them, it can still ruin your reputation as people talk.