Thought this would be fun!
All you really need is a team, an idea for the puzzle, and a badge. Feel free to be as detailed as you want.

Resources for making things easier:
https://pokecharms.com/trainer-card-maker/
https://pokepast.es/
https://richi3f.github.io/pokemon-team-planner/national_dex.html
https://richi3f.github.io/plan-pokemonteams/

And feel free to use any templates you want.
Most of all, have fun!