Here's generally the way Zach and I approach writing an episode of Obituary: Things usually start with talking out scenarios or character interactions that would prove fun. Once we've explored the ideas and settled on one, we talk out the beats.
Zach is usually the one to take a first "Skeleton pass" where many (but not all of the bones) would be placed. I then take a crack at it, and after that initial volley we talk through what we're still missing or things we discovered while writing (for either the purpose of taking the episode in a different direction, or for the sake of storying or setting up a bit for later). Whoever then has a better sense of what the script needs gets the next pa