I used to think the key was throwing in random traits like 'drinks tea' or 'likes quiet,' but that just made a cardboard cutout. What actually clicks for me is figuring out their negative space—the things they're indifferent to, the jokes they don't laugh at, the conflicts they walk away from. Chill isn't just a vibe; it's a set of deliberate non-reactions.
For my 'The Legend of Korra' OC, I gave her zero interest in political drama. While everyone's shouting in council meetings, she's outside fixing a radio, not because she's above it, but because frequencies make more sense to her. Her calm comes from a focused, narrow passion, not from being generically zen. It's the absence of scattered energy that reads as chill, not the presence of sage wisdom.
Another angle is physical economy. A chill character often has slower gesture patterns, less filler dialogue, and a habit of settling into environments rather than dominating them. I notice them reacting to weather or furniture—leaning into a sunbeam, testing a hammock's sway—stuff that shows they're present but not performing. That's way more telling than just stating they're laid-back.
Conflict tests this, obviously. When the plot demands a reaction, their chill might manifest as a delayed response, a diverted solution, or a quiet breach of protocol that's effective precisely because it's unruffled. The tension between their inherent calm and the story's chaos is where they stop being a mood board and start feeling real.