1. Concept

Before you do anything else, imagine the monster. What is it? What does it look like? What does it do? Does it live alone or with others? How does it fight, eat, and live?

You'll usually have some ideas for the monster when you start this process. If not, or if you want something to spur and guide your creativity, then use one of the various sets of monster creation tables in Book II.

Another trick is to pick a monster from more traditional fantasy settings, something that isn't present in Stonetop. Identify what you find most interesting about it (its look, its powers, its symbolic meaning, its behaviors or relationships to others, etc.) and craft a similar monster that "fits" into the mythos of Stonetop. For example, if you're a big fan of ropers (cavern-dwelling monsters that look like giant stalagmites), you might decide to place something like that in the Labyrinth, keeping its powers but changing its lore to align it with the Things Below.

You should have a decent grasp on the monster's concept before you move on. Your concept might change and evolve as you work, but this process fleshes out a concept that you already have. It doesn't generate the concept for you.

I want two powerful Fae guardians to protect the Green Lord's burial vault. They'll appear in the Hall of Offerings and greet anyone who makes it through the Halls of Humility and Gratitude. I know that they're loyal to their Green Lord master, and that they control access to both its constructed afterlife and its actual, physical burial vault.

I work through the procedure for Creating Fae (Book II). I've already decided that their preoccupation is "guarding." I roll a 2 for size ("large"), and a 2 and 7 for aspects ("antlered/ hooved" and "treeish"). I roll a 2 on a d6 to see how person-like they are. I'm picturing tall, powerfully built tree-men with woody flesh. blank faces, and elklike antlers.

For talents, I roll a 6 ("messing with time, space"). I think that they can teleport intruders around and can vanish or appear as they please within their little domain. I also pick "cursing/ blessing/giving/taking." I think they extract promises from those who come before them, and curse those who break their vows.

Looking over the remaining tables, I think these Fae were bred from tree spirits to help protect their Green Lord's afterlife. They remained loyal during the Fae rebellion, and maintain a fierce protectiveness--hence the tomb being intact.