One book at a time, one movie at a time (like if I couldn't finish a movie in one sitting I finish it before starting another one, unless I just uber-hated it and rage quit). It's weird because I don't insist on watching only one TV show at a time. π€·π»ββοΈ
If I immediately start a new one depends on how the previous one hit me. Sometimes a book can affect me in a way that I need to sit with it a bit, let it settle, because I find myself thinking of it still when trying to start something new. But if it's just a breezy read that doesn't linger on my mind then I can easily start something else. "The Buffalo Hunter Hunter" had such an unsettling ending that I couldn't start anything new for like a week or more. My brain wouldn't move on from thinking about it. I had a similar experience with "A Head Full Of Ghosts". That ending still sticks with me. I heard it's being made into a movie and I just know Hollywood is going to screw it up so bad.