Also always ask if they can use the phone or the computer (even if you have been told they are free to use it at any time).
Always ask if there is anything you can do to help - i.e. never assume that the employer wanted her undies folded or her bed made (basic respect of privacy).
If your employer has a house in town or you become friends with someone in town always ask to stay. Even if they say you can stay anytime.Five years ago a teacher became friends with a governess, invited her to stay once and after that the governess just rocked up and stayed all the time, sometimes bringing other governess or male friends with her. If employer has a house in town, some might not want all the governesses rocking up expecting to stay. Talk to your boss about expectations. One of my employers has a town house with heaps of beds and was more than happy for us to stay as long as I let her know. I always said who was possibly staying and cleaned up after we left.