Five sleep interventions with strong research backing.

1. Fixed wake time daily. The strongest circadian anchor.
2. Morning light 10-15 min. Resets the clock.
3. No caffeine after 2 PM. 5-6 hour half-life.
4. Cool bedroom (65-68°F). Supports sleep-onset temperature drop.
5. No screens 60 min pre-bed. Blue light + stimulating content.

Fix these five; ~90% of sleep complaints improve within 2 weeks.