Some insight I've gained in the past couple months. Seems to be working out so far...
  1. Different music
    I think when I was 16 I read that James Cameron did this when he was writing Aliens and Rambo 2 or something, only he also had separate desks. We don’t all have the physical space for that. But using spotify its pretty easy to make a playlist of different music, that will help you get into the mental space for each project.
  2. Jump off when you hit a wall
    This instinct probably comes from hearing about how the Coen bros wrote Barton Fink. and it works. When you know you have multiple things then you have less of an excuse not to just move on if yr stuck or bored. I vary it though, sometimes I spend a whole week or weekend on one thing, other times I switch every few hours.
  3. Have a partner
    Okay this one is cheating, but it’s true. writing multiple things at once is easier when you have two people, in fact I would argue that its better for two to have multiple things going at once, as the business seems to cut down on ego and keep everyone on task. But there are plenty of writers who can manage this solo. So maybe I’m just dumb.
  4. Try to always be in different stages on each one
    It would be very difficult to start 4 first drafts at the same time. But starting one, while outlining another, doing producer’s notes on a third and making notes for draft 2 on the forth, is a lot easier. Each task is a slightly different set of problems to solve.
  5. The more different they are the better
    This is sort of a continuation of the previous thing... An adaptation is very different from an original, likewise TV vs. Film, so the greater these distinctions can be between the various projects the easier it will be to engage with their uniqueness. I doubt anyone could write 4 different vampire movies and expect each one to hold its own.
  6. Setting goals can be good
    This one I’m still on the fence about, but its really been working recently. My usual attitude is just show up and get done what you can. But in the past month I’ve really gotten a lot out of giving personal deadlines and page counts for a day's work. Sometimes it feels like I’m tricking myself, but that’s not a bad thing.
  7. Communicate and prioritize time
    Everyone wants everything ASAP. But you (and yr reps) are the only ones who know how much is on yr plate. You can’t just do whatever anyone asks of you. But you can learn to determine what needs the most attention soonest. And be clear with all parties about how long things will take.