Waterfall braids are very popular on hair blogs right now. Here's an easy faker version that I saw posted somewhere online by a blog reader. It's got a very cute, clean look to it. Little Miss and I have been doing this one a lot lately.
Start with a side part. Part out the front section of hair and bind it off with an elastic, but not right against the head...
Do a pull-through at an angle, as shown below:
Part off another rectangle behind the front one and bind it off, adding a little hair from the front section to it (and leaving most of the hair from the front section hanging down).
Do another pull-through. Keep this up for as many sections as you like. We did five: