Building Characters and Creatures
Player characters and every named person in the world use the same file type and the same rules. There is no separate NPC format, which means anyone in your cast can be picked up and played.
Fill the personality fields even for minor people
The likes, values, dislikes, fears, and flaws lists are not decoration. The GM reads them before writing a scene and plays the character consistently with what is there. A character with three filled lists behaves like a person across twenty sessions. A character with a good backstory and empty lists drifts, because there is nothing to anchor them turn to turn.
The minimum for anyone worth a file is concept, drive, trouble, and a description specific enough that a search finds them. Everything else can be filled in as play reveals it.
Trouble is the field that does the most work
Drive tells the GM what a character chases. Trouble tells the GM how to complicate a scene without inventing anything. Write Trouble as a live problem rather than a personality note. Owes money to people who collect in person is a Trouble. Somewhat impulsive is not.
Condition and bonds are live state
Both are meant to change during play, and the GM instructions update them the turn the fiction does. As a builder, seed them honestly rather than leaving them blank. A character introduced already carrying an injury or a strained bond arrives mid story, which is almost always better than arriving neutral.
Keep secrets in the right field
Every one of these types has a GM only field, and the GM is instructed never to show, quote, or hint at what is in it. Anything the players have not earned belongs there rather than in the description. The description is public, and players do open files.
Creatures
The Creature type is character shaped without the twelve humanoid worn slots. Same three Feat lists, same tier ladder, its own carried and worn gear, its own condition and bonds.
Use it for anything alive enough to want something. Beasts, mounts, machines with a temperament, spirits. @Missing file is the worked example, and the thing it demonstrates is that a mount with a want and a temperament produces scenes, while a mount treated as equipment produces none.
Fill wants and dangers on every creature. Those two fields are what let the GM run it as a participant rather than a prop.
Cast size
A campaign runs well on a small number of deeply filled characters and a wide, shallow bench. Resist writing forty complete sheets before play starts. The GM has a dedicated instruction for creating a character file the moment someone starts mattering, and it does it reliably, including for people who are dead, missing, or have not appeared yet but keep being talked about.