The prefrontal cortex is the part of your brain that regulates self-control, or better said willpower. It is one of the parts of the brain that undergoes a great transformation during puberty. A period in which most parents function as your 'external Willpower' until your prefrontal cortex is ready to take that responsibility. What is important for your prefrontal cortex to function properly?
Enough sleep. Most research nowadays states that people need 6.5 - 7.5 hours sleep per night in order to be most happy & healthy.
See the Sleep exercise for more information on sleep exercise.
Proper physical exercise. A very safe bet is yoga exercises. Why? Because yoga can be both an intense physical exercise and a relaxing exercise that cultivates your spiritual being as well. Looking for inspiration? Do the Yoga exercise.