Customizing my cabin... hmm... I would have a Cross on the wall, underneath it a table with my Bible and Rosary, a big screen on the wall, black furniture, a black and violet stereo, a fake fireplace, black bed sheets, my violet laptop on a black table, a black bookcase with nothing but Star Wars games and books on it, and on the opposite side of my room, a little play area for my pet black panther, dark violet floors, a closet -- half of it is filled with nothing but black bows and arrows and black colored semi-automatics; the other half if all my clothes and shoes. And a big picture window up top to see the stars, too... now this is all if I could make my cabin how I wanted.
But I will take whatever BioWare gives us as long as it is not ugly. I really enjoyed my cabin in Mass Effect 2 and 3.