When partnered, I have to sleep on the side which puts me between her and the bedroom door. The reason is because if an intruder breaks in, I feel I am better positioned to protect her and get "at" the intruder faster. I have always had a very protective nature. It's my job.
Generally when single, I am sprawled all over and just try not to mash a dog. Lately, I am doing good to crawl in between dogs and hope I can stake out enough wiggle room for myself. Jennifer (pocket - pittie) doesn't take up much real estate but Kevin (100+ lbs. mastiff-bully mix) likes the middle half of the bed.
I have often thought about getting him his own twin-size bed.