Follow these steps:
1. Strip to deep structure
Describe the problem's deep structure without domain language: entities, relationships, constraints, goal.
2. Search distant domains
Find a structurally similar solved problem outside the current field — biology, other industries, physical processes, games, social structures.
3. Study the solution
Study how their solutions work and why.
4. Map it back
What transfers directly, what needs adaptation, what breaks?
5. Extract the principle
Extract the underlying principle that makes the solution work.