All five of my self-published Labyrinth Lord adventures have been for low-level parties. I want my next published adventure to be a high-level or mid-level adventure. What does that mean? I recently quantified that in a series of posts. While I've more-or-less settled on my answer, I still aknoweldge that it fails to account for various important factors such as trap complexity, number of monsters encountered, and monster special characteristics among other things.
Doing a little high-level adventure research, I pulled my copy of Queen of the Demonweb Pits off my bookshelf and started compiling the monsters as I read through each room description. I got thirty or so rooms into this endeavor before I stopped with the following data:
Name/HD/HD Bonus/Number Appearing
I wasn't even close to reaching the spider dieties and larger unique monsters, but it was clear that adventure difficulty was more about monster's special abilities and number encountered than Hit Dice. I mean, good grief, 30 bugbears? 20 ogres? These are huge numbers and, frankly, a bit of a nightmare for in-game data tracking even if you admit the liklihood that a high-level party will likely defeat them in battle. The mechanics of such a battle are likely to become too tiresome for my own tastes.
Therefore, I will use high numbers of monsters encountered very sparingly, if at all, in the course of my mid-level adventure. I currently have nine original monsters brainstormed, and I'm using the low encounter number + high Hit Dice + multiple special abilities method for generated a challenging adventure. The number of traps will also be exceptionally low.