I used 4 beads as height, because of my lack of ponybeads, but anything will work

Next, you add a bead and go back trough the 3rd bead (see picture)
Add another bead and back trough the first bead

Because you have so many layers, you can pull tight as much as you can, and still have a stretchy bracelet.
After pulling tight the first time, you should end up with this

After that, you go back up, again add a bead, go trough one, add one, go trough one, pull tight

I'm missing a picture here (my cam broke it!) but then you just keep pulling tight and adding more rows
After a while, making the petern you would like, you end up like this

(I tight my thread start to the bead so I didn't have to hold it the whole time)

My wrist is really small, so i ended after 18 beads (sideways)
That's how you measure how long it should be (try to keep the patern complete)

Next, you pull your thread back trough the first row, 4th bead

..

Now go back and trough the last row again, and back to the first
Keep doing this untill all beads have 2 threads trough them (only 4 rows for me lol)

Pull this tight, and now all you have to do is knot your threads :D

You should end up with something like this