How to train your brain subconsciously to fall asleep in 30 seconds [1]. (1) remove caffeine in training period (2) good diet; (3) exercise; (4) wake at same time, no lingering - which trains your brain it's all it gets, which incentives brain to fall asleep at the same time to adapt. It's the lingering that teaches the brain that it's ok not to wake up, so brain never trains itself to fall asleep immediately. (5) caffeine can be added back once brain is trained.
Herbal stimulants - peppermint, cayenne, ginger, cinnamon - [2]

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