If you GM with props and aids that represent in-game content, then start with your most restricted design element and grow your design around that.
For example, if you like to have NPC portraits or graphics, then instead of designing the NPC first and questing everywhere for the perfect picture, start with the picture and create the NPC around that.
This works for all kinds of design inspiration:
- Sound effects
- Theme songs for villains
- Pictures of scenes
- Pictures of locations
I do the last one often. I start by flipping through the monster book until I land on a critter that catches my interest. Then I design in-game encounters based on the monster entry.
My preference is to start with the fluff. That brings the good work of monster designers to full fruition in my campaigns. Environment, groupings, lair preferences, treasure type – all this can feed into world building, adventure design and encounter formation. Legends, events and rumours based on this information feed plot hooks and encounter hooks, or just fun campaign background noise.
Sometimes I do need a straight-up combat encounter, and unless I know the time and location, I will pick a monster of sufficient difficulty at random and start forming the encounter around that.
The spirit of this tip advises you to begin designs with your biggest restriction and work outwards from that. It makes things faster and easier for you.