I take a 1 week deposit and apply it towards the first week of care. It's not the best option I'll admit, but it works for me and I have enough back up that if someone dashes on me I'm ok.

I also accept payment at the end of the week for that week. Must be recieved by pick up. Most parents pay me at drop off Friday

I think you need to design your business the way you see fit.

I don't suggest taking friends or relatives and I do suggest having some sort of policies or a contract done up. Too many of us start without and regret it later.