How do you fall asleep?

Ok, so I've noticed a bunch of people here have said that they create little stories and scenarios in their heads when they're trying to fall asleep. Is this something that you do deliberately? Or is something that just happens?

I fall asleep by letting my thoughts spin out of control - I let them go wherever they want (which, as you can imagine, is not necessarily helpful if I'm thinking about something painful or unpleasant - those are the nights when I tend not to fall asleep at all). In that jungle of thoughts, my mind often plays out weird scenarios or re-imagines events in the last day or so. There is nothing deliberate about it however.

So -
First: how do you fall asleep?
Second: if you create these quasi-daydream scenarios, is it on purpose as a tactic to fall asleep or is something that just happens?
Third: how long does it usually take you to fall asleep?