After some trial and error on this style, I have finally found some success today! Hooray!
To start, make a part on one side at the top of the head. Take a large section from one side above the ear and divide it into three equal parts as if to start a french braid. For ease of directions, I will say to start on the left side, but it doesn't matter really. Cross the left side over middle, and then right side over middle. Now to add hair, you will only be adding from below the braid. The hair that is above the braid will fall down behind the place where you are braiding and will be gathered in with the hair below. So add hair to the left side and cross it over middle. Cross the right side over the middle without adding hair.
Repeat until you have reached the neck at the middle of the head. Braid a little way down and add a temporary elastic. Repeat on the other side (adding hair only to the right side sections). Join the braids together at the back of the head.
One of the problems I came across when trying this out was that the braid had a tendency to roll down and show the inside like this:
I tried at first to compensate by adding bobby pins. That was only somewhat successful. If you want to go all out with a zillion flowers, hot gluing the flowers to the ends of the bobby pins and pinning up the braid would be a great solution. That won't do for a regular school day, though. I tried pulling one side tighter than the other, but that seemed to make it worse. So finally today I just made everything sort of loose and I didn't have that problem.
Another problem I ran into was that the hair at the back of the head kept getting bumps in it. I wanted it to lay smooth, but it wouldn't. It would fall flat until I got to the next plait. When I cinched the next part of the braid, the place I had already braided would stick up. It looked like this:
I solved the problem by spraying that section of hair with water before braiding. That made some more friction and wouldn't let the braid slide up and raise bumps. Also keeping the braid loose helped to keep it from shifting up. A much neater look:
After joining the braids, there are two ways to do the rest. I'll show both. First way is like my braided braids post. Start by making three small braids like this:
Then divide the whole tail into three, each with a tiny braid. Braid it all up, adjusting the little braids to show with each cross.
The other way, you still make the three tiny braids, but you wrap them around the larger strands before braiding.
I wrapped them all clockwise, but I would do one counter clockwise next time.
Wrap the tail by taking a thin strand at the back, wrapping it all around the elastic twice, and then tucking it back down into the elastic at the back. It helps to pull out the elastic to get the hole ready before wrapping the hair around. A topsy tailer could also help to get it tucked back down.
For the finishing touch, a flower can cover up the top hairband. In the movie, Rapunzel had a big blue flower covering up this spot. You could technically join the braids without a hair band by combining each three strands with the three strands from the other braid and braiding it from there, but that is more difficult.
Also, if this braiding technique boggles your mind, just do a simple dutch braid instead.
As a footnote, if you have seen the movie: Do you remember those four little girls sitting by the fountain doing each other's hair? And how their jaws all dropped when they saw Rapunzel's hair? That was my favorite part of the whole movie. I could totally relate to those little girls! lol