The only reason I am even considering joining this discussion is that I’m coming to the CR straight after my first babysitting stint in about two years. But here goes…
Carrot and Stick. Not too much carrot as to reward bad behaviour (Off the point, Spellcheck, if you try and give me American spelling once more, I’ll dismember the annoying paperclip), not too much stick as to inspire resentment. It works.
Talk to them with respect. This does not mean flattering them or talking to them as adults. Just respect.
be firm. If you go back on your word once, they’ll push you to do it again.
Be their friend. What I mean to say is if you are generally nice to a kid, and really listen to them, they are far more likely to listen to you at a later stage. I don’t mean act like a friend rather than a parent, just that negativity alone does not get results.
And finally, every single bit of this advice will go straight out of the window when I get kids of my own, and am just desperate to go to sleep. But it will serve nicely as a diary entry to remind me in future years that I once had what could be considered principles.