If you want to try this either by yourself or with a group of friends I definitely recommend buying extensions. These are the extensions I bought. They're cheap and synthetic BUT they come in a bunch of colors and for the purposes of braiding they're just fine to use in order to really BULK UP a lazy braid;-)
Here's a great tutorial on how and where to place your extensions when doing a plain dutch braid.
Here's the tutorial I used to learn how to make the dutch fishtail braid. It's not the easiest braid to learn but it's kind of like riding a bicycle. Once you learn it's pretty easy.