Under the Cloak

Going under the cloak can be done for a short while or a long while, and it means basically that you literally get a blanket or a cloak and lie underneath it, and then depending on how extreme you want to make the thing, you put rocks on your chest, as the Druids used to do, to depress your breathing, and that alters your state. You can have your helpers cover you up with earth, all but just a small area on your face so you can still breathe, but you're going to be carbon-dioxide-stressed, because it isn't the same amount of oxygen, and it is stressful.
You want to have ground crew for this, so you can stay alive. They need to be able to very unobtrusively check on your physical well-being, to keep their energy to themselves, and be comfortable in the space. Warding is good if they can do it, but it's not always necessary. If you're going to go and do something like this you probably want to put up wards first anyway, however you see those things. The ground crew keeps checking that the blanket is still becoming moist from your breath. If you stay there for many hours, then you have to get used to the idea that you'll probably have to urinate, so you might want to dig a shallow grave or trench and lay there on a sheet and have it all covered over except for the breathing part of your face. You can be there for twenty hours if necessary. The Earth is quite a good insulator, and it's a weird experience.
Traditionally it's three whole days, but that's pretty severe and rarely done. You can do a whole long fast before that so you don't have any issue with solids, but you will urinate. You need water; if it's less than 18 hours you can do without as long as you don't have any heart, kidney or bladder problems; you won't do irrevocable damage, but for more than that you need water. We modern people have soft bodies and we aren't used to hardship. So you would set up a little tube or a camelback that you could sip from without actually getting outside interference. But three days is excessive, for the most part. Overnight is more than enough for most people. We find that usually six hours is more than enough for most people, and you can certainly do without water for six hours.
The experience of having the earth on you is weird as well. The weight of it feels strange, and you also have the earth over the third eye part of your forehead. You get cramps and twitches, huge claustrophobia, panic attacks and weird sensations, even if you're not usually prone to it. You can't move, and you definitely get sore, and that's kind of part of the deal, detaching from that. Of course, spending three days under the earth is neither safe nor basic. But using a mummy bag for a few hours...even just spending the night sitting vigil in the woods is enough to creep most people out. And that's not a bad thing...getting a good fear on will put you into an altered state.
In contrast, float tanks are great, but that's very high comfort. When I do a float tank, I kind of feel like I'm cheating, because it's not hard at all. It's really nice. It's dark and weird and creepy and you can't distinguish the boundary of your body from the water. You can also make a modern witches' cradle or cat's cradle out of a good army surplus hammock and just tie it up, but I've found it rather time-inefficient.
We do a thing where we just stopper up the ears and the eyes and put a hood on and get in a mummy bag and be wrapped up with duct tape. If you have someone who is adequately knowledgeable about bondage, you can do it as being tied up. Make sure that there's plenty of room for circulation. Or use a big sack, a mailbag or spandex body bag, and a darkened room, and just lay there. The first hour, you'll feel silly. The second hour you'll feel silly and uncomfortable. The third hour you'll feel silly and uncomfortable and claustrophobic, but after that it starts getting interesting. It's a very labor-intensive way of doing things. But the key things are regulating and/or limiting the breath, sensory deprivation, and doing awareness exercises, and the length of time that it goes on.

Supported by Lydia Helasdottir and RavenKaldera