For most people it takes 15-30 minutes to fall asleep, sleep physicians say. To fall asleep fast, try guided imagery or sleep apps. Establish a bedtime routine and only use your bedroom for sleeping to train your brain to fall asleep quickly. Avoid screens, heavy meals, naps, and caffeine later in the day. You can also start journaling or using a white noise machine. If your sleep is disrupted at least three nights per week for at least three months, you may meet the criteria for chronic insomnia and should see a board-certified doctor.