Lol. Do you have a basement? Can you do it on ground level.

I usually just sit on my bed and do it, laying back is too uncomforable because everytime I do it I get these weird cutting sensations down my back.

My advice, take in ONE BIG HIT, and that's it, hold it in until you feel like your going to make youself pass out, let it out, you'll feel it pretty soon, put your smoking device down IMMEDIATELY after inhaling and get into the position you want to be in, whether it's laying on the bed or sitting down or whatever. I prefer to be in a place with not very many sharp objects (since I do like to get up for some reason) or things that I can hit my head on, or things that I can break (glass etc etc).

20x smoke isn't as rough as 15x, I think the lower the number, the closer to the leaves, the more harsh the smoke is.

Um..You can play some music, I find it best to have something to interact with, a TV, a song, the computer, somebody online, it makes for the best trip for some reason.