I have found deep breathing exercises to be the best remedy for insomnia.
The primary cause of insomnia is that the sympathetic nervous system is not shutting off. The sympathetic nervous system is also known as our fight or flight system or stress response system. Because most people are living high stress lifestyles, eating a poor diet and being exposed to numerous environmental toxins on a daily basis, all of which activate the stress response system, the sympathetic nervous system gets stuck in the on position. When the sympathetic nervous system is dominant, we experience, high states of stress, hyper alertness, nervousness, inability to relax and sleep.
Deep breathing exercises, when down properly by breathing from the abdomen, turn off the sympathetic nervous system almost instantly; which allows the mind and body to relax and enter the sleep state. Additionally, deep breathing exercise stimulate the release of serotonin, endorphins and other feel good neurotransmitters in the brain that oppose stress and incite relaxation.
However, it's equally important to reduce exposure to environmental toxins and remove foods from the diet that trigger the sympathetic nervous system like coffee, soda pop, chocolate, sugar and other refined junk food.