first and foremost most of the stuff is obvious however as they always say common sense is not as common as it should be.
Ask the customer what their shoe policy is.
some customers don't want you wearing shoes in their home and which point have booties ready or be prepared to take your shoes off.
Keep your footprints small
if you have a lot of work tools or things that you need to do the working their home make sure you keep it consolidated to one location that is out of the way and not intrusive.
walk the house with the customer
don't go into any room that they have an authorized you to be in or they haven't walked you through.
if you need to hunt something down or find something it's usually best to ask the customer first however if they're not interested make sure you tell them that you intend to look for a specific item or let them know ahead of time of your intention to roam around the house.
this is incredibly obvious but this is someone's home their personal space there's no good reason why you need to get into anything for any reason so don't do it.
Always give the customer the right of way
if you're working in a hallway or a path that is inconvenient the customer needs to get through give them that priority unless it's incredibly inconvenient for you and which point you can apologize but keep in mind that you're the invader in their home.
Stick to the work
the customer doesn't mind being social but keep in mind that the end of the day they're going to receive the bill if they think you chatted him up too much they make considered fighting the bill.
if they're insistent on wanting to have a conversation with you make sure that you look busy or are actually solving something while you talk with them.
Don't take pictures
you wouldn't want someone walking into your house and flashing up the camera so do the same courtesy to them don't take pictures of their home no matter how beautiful or how elegant the view is.
Privacy is very important to people including you.
Clean up after yourself
Nothing bugs people more than to clean up after someone else misses a true statement across-the-board no matter what you're in.
Be sure to have cleaning supplies potentially a vacuum if you're intending to make a mess.
Do good work.
You should always do work as if you're never going to need to come back. you should always wants to make sure that if someone comes back it might not be you so it's always good to leave information behind that helps the next person cuz you might find out that next person is you.
Watch your Language
Dont swear or get two loud. The customer knows your there in their home. Try to make them feel like you don't exist.
Dont ask for food or drink
If the customer offers food or water/drink feel free to take part. But never ask for such things. Pack in and Pack out. Its not your home. So assume your camping. If you want a drink Pack it in in a closed container. If you need to eat. Do it outside or behind the van.