I never did it at home, I used the college's dark room. Have you ever used a dark room Ravein? -coz it is mucheous fun, and I would urge you to try it out if you've not. A home dark room sounds fun.
I would suggest that you assign a side of a coin to each of your flatmates, flip the coin, then who's ever side turnt up, kick that one out. Apologise, give cookies. Then get out the black paint!

Just kidding...
Im not really, just do it, mwha hahaha *composes self*I'm a really nice person, really, I am