Over the past year, perhaps longer, I've been experimenting with different ways of doing my prep notes. The last couple weeks I've kind of settled on a way not too far from where I started (shockingly enough) but I've noticed certain trends that definitely came up over the year, and they're things I want to keep exploring.
In a simplified manner, my notes start off with a simple recap of last session. I do this with four bullet points where I highlight the big things that happened last session or stood out to me. From there, if the PCs are starting off in a situation that began last session I'll have a reminder for myself on where they are.
Beyond that I tend to section my notes into: Situations and Locations, in that order.
By this I mean that situations take priority. So if there is going to be a fight on a bridge, the note header will highlight it is a fight on that bridge. From there I will give a brief description of the scenario, but most of the notes will focus on the situation.
However, if the PCs are travelling a long distance, and that travel will mean significant changes in scenery, I will have simple locational notes about what they see, how the terrain changes, and some other sensory information to give them a sense of the distance traveled.
Even then, most of my notes tend to be detail and description light. I do this to leave myself room to pivot in scene or if the players go somewhere. I also do it because it helps keep prep light, and - frankly - sometimes I am scrambling to get things together.
That said, I've found some useful additions. If I know the PCs are going to a "hub" location (place where a lot of things can stem from) I will do my best to prepare a separate note file for the location that details key spots, NPCs, and other information. These notes can be opened up separately from the session notes and referred to as needed. I find this a lot easier than putting the notes into the session notes, because you never know when you're going to need them again.
I've also found putting some dialogue into the notes can help catch a character's voice - and help me actually RP an NPC. I need to do this more, but it is a good tip and I'm glad I picked it up...even if I don't remember where.
But what about you? How do your prep notes look? Do you even do prep notes?