Doing things the way their owners usually do won't give them any surprises and they are likely to feel more at ease.
Secondly, you don't want to be starting habits that the owner will then have to deal with when they get back.
Other times, you may in fact be using their bedroom for the duration of your stay and hence they may not be able to accommodate you until the day they leave.
In any case, it's good to schedule a little time with the homeowner before they depart so that you can meet, they can show you where things are and you have the opportunity to ask questions.
In addition to the physical whereabouts of things, it's important to ask lots of questions about the pets' routines.
For example, when and where they are fed, how long they are walked and at what time of day, where they sleep and whether there are particular parts of the house that are usually off limits to them.
There may also be confusion as to how some things work in a foreign country, especially if all the buttons are in an unfamiliar language!
The homeowner will likely give you a tour and point out anything you need to know, but if you aren't sure, just ask.
This is important because it maintains consistency.
For some pets, having their owners away is disruption enough to their usual routine.