Collaborative writing on Sproker: how do I set up a chapter so the next writer can succeed?

I've been thinking about this a lot since I started contributing here. When you write for a traditional novel, you know what's coming. On Sproker, the next chapter is being written by someone who has read yours but doesn't know your plans. So: how do you write a chapter that gives the next writer a good launch point without constraining them? Things I've found that help: **End on motion, not resolution.** A character walking toward something, making a decision, receiving information. Not: "and then she understood everything." Yes: "she picked up the phone." **Plant three options.** Introduce a detail, a relationship, and an unresolved tension. The next writer can pick any one of these as their thread. If you plant only one thing, you're railroading. Three feels like a world. **Be specific about the wrong things.** The room doesn't need a specific wall colour, but the smell matters. The character's hair colour doesn't matter, but their way of speaking under stress does. Specific sensory and behavioural details are generative. Specific visual details are constraints. **Don't solve your own mystery.** If you introduce a suspicious character, do not immediately reveal whether they're suspicious for a reason. Let the next writer decide. Anything I'm missing?