Get less sleep
Wake up very early and stay up late
Increase stress exposure
Do intense exercise frequently
Drink caffeine, especially on an empty stomach
Skip meals or fast for long periods
Eat very low calories
Consume lots of sugar and refined carbs
Drink alcohol regularly
Overwork without adequate rest
Expose yourself to cold stress
Use nicotine or tobacco
Take corticosteroid medications only if prescribed by a clinician
Consult a healthcare professional before trying to raise cortisol