That's pretty much what I do. I sometimes also put four or five very thin braids in and let those hang down.

I had two teachers in college and grad school who both wore long hair that ran from below their waists and sometimes as long as the backs of their knees. Both of them swore by hair braiding (in various numbers of braids and thickness) for just about any situation where they had to deal with their hair being anything but loose down their backs.

I have hair similar to yours - I have been experimenting with making a part across the back and leaving a section down. Then I make two buns on top. I wrap a scarf around and then star stuffing stuff in. I don't have a good picture of the back, but I put some pictures in my profile that kind of show it. I had a white lily and a beaded piece in back (one of those things that has a stick that goes through two holes) that I used to connect the buns. I also had porcupine quills and a stick with an animal dangling from it. I think that's it.

I used to have the uber-long hair until quite recently. It was difficult to do stuff, but you get to be super creative. If you or someone you dance with can french braid, try playing around with circular braids. You can circular braid 1/3 and leave the rest loose, combine braids with buns, or do 1/3 or 1/2 buns with the rest loose. Then, of course, bedeck yourself with pretties and shiny things.

If you ever go to celtic or rennaisance faires, it is SO worth going to the braid ladies that often are there. Bring all your hair pretties and tell her to work them into the braids-I did this once and the outcome was AMAZING!! Tip her well ;-) and take photos so you can sort of attempt to re-create the look.

Or just put it up in a big messy bun and stick sh*t in it!

I have really long, super curly hair, which just doesn't always work for what I'm going for (straight, smooth, etc). I have a couple majestic hair flowers: www.majestichairflower.com/ and I coil my hair up into a bun underneath them and will use fake hair extensions to create more elaborate hairstyles. I get the decorative effect from my natural hair but can then have more sleek looks for everything else. And it's so much easier to create decorated long hair braids with extensions and then attaching those than it is to do it with your own hair.

I also have very long hair - was past my knees until recently, now mid-thigh. I chopped off about a foot so that I'd finally be able to dance with it down if I wanted.

However I do tribal mostly, so most of the time I just put my hair in a high bun and then use that as a base to stick things in it (yarn falls, tassels, hairsticks, flowers). I've also done a Central Asian style with lots of little braids and am Uzbek hat - I love the look although it takes extra prep time. That one's useful for keeping it from tangling in things while showing off the length.

AFAIK Rachel usually puts it in two or more buns and then sticks all sorts of stuff in it.

Central Asian style: people.tribe.net/cb741971-...ac4c33ed2a
Default tribal hairdo: people.tribe.net/cb741971-...104322a6d3

Sandi from FCBD has really long hair and she does a really cool Frida Kahlo look sometimes. She puts her hair in 2 high ponytails, braids them and then sort of figure eights them on top of her head. She also before braiding, puts a scarf in there and then does the figure eight to make it look really authentic Frida. Then she adds her doo dads, flowers etc. You can do a google search for Frida Kahlo images and you can see what I'm talking about. Looks beautiful. Just an idea.
Good luck!

My hair is about the same length and thickness as yours (I'm a redhead) and I've had a lot of luck with creating two pony tails towards the top and back of my head. Then, I take each pony tail and braid usually about three braids per pony tail. I will often add feathers to the end of the braids or kuchi pendants. Because my hair is so long and very heavy, I keep the pony tails from falling by using a large safety pin (I know this sounds wierd) and I litterally pin one pony tail to the other across the top of my head. This also then offers me a place to add extra stuff by clipping it to the safety pin. I've found pony pony tail holders at Walgreens that have hair on them with long braids. With as much hair as I already have, I actually use these. It makes things so much easier. I gust braid my hair like I mentioned above, add the pony taill hair extentions (which have all my beads and feathers already on them) and I'm done. Plus, you can run the safety pin through these rather than your real hair. I'd be happy to send you a photo of the finished product if you like.
Sajah