So how much preparation went into the caving adventure?
In short, a lot. That session took more preparation than pretty much any of the other sessions I've run, including the one with the little 3D diorama of the old abattoir which I made comparatively easily.
For this adventure, other than all of the brainstorming, pre-planning, and ensuring the players put enough thought into their tactics and equipment that they weren't left with their pants down around their ankles at the main event, I also trialled a few different techniques that were quite successful.
I created a desk of cards instead of a map and that required coming up with, and writing down, around 60 possible encounters, from cave structures to enemies and their statistics to traps and pitfalls. You can find more information on the creation and use of these cards over here. This put the player's choices, quite literally, firmly into their own hands as I'd randomly draw 7 cards and they would randomly pick 3. I would then use them as a guide for how the next encounter went, whether by combining them into one event, stringing them out, or what-not.
I also created cards for everyone's equipment so they could swap weaponry and equipment at a moment's notice, use it up, mark off ammunition, and all the rest with a lot of ease. It took up a fair bit of table room but worked out quite well. This also prevented the players from randomly declaring that they had packed something they hadn't or chosen to bring something they had chosen to leave behind due to weight limits.
Okay, so there were still a few declarations where players later assumed they'd grabbed something they'd left behind, but I could easily disagree. All of the equipment anyone had indicated had been placed, in card form, in the center of the table and any equipment declared at the last minute was hastily sketched out on extra card paper. If they had literally chosen to take it with them, they would've taken it out of the pile, so there was no chance that I'd simply misheard, forgotten, or even not heard that they'd brought extra gear due to the kerfuffle of multiple character conversations that always occur before a big adventure.
I also created some Madness, Sickness, and Status Cards. This made it easier for people to remember what sort of bonuses and penalties they had, helped me keep it all straight, and helped keep some of the madness issues under wraps. It also kept the game from slowing down as I didn't need to explain the rules. I could just give the rules to them and they could keep track of it themselves from there.
I also created little clocks on card with the big hand pointing to the hour where they'd get their faith back, since I was running a timeline in my head. That way the players and I wouldn't forget when someone would be regaining their Faith.
I also set out tokens for their willpower and faith so they could spend them freely, be aware of what they had, swap faith, and be rewarded with willpower with relative ease. It also meant they could see at a glance what their reserves were. This worked out quite well and spend things up quite a bit.
I kept their Health levels hidden so I just needed a piece of card kept aside for this one.
But yeah, a fair bit of preparation went into this one.