Just relax in the bed and wait until sleep returns. Try reading, listening to music, which will ease you and will reduce your mental tension. Do some light physical activities such as rolling from one side to another, movement of legs untill you feel sleepy. Avoid consumption of alcohol especially at night. Cut down on chocolates, coffee, tea, soft drink and smoking especially in the evening and before going to bed.
Mental stress is the main cause of insomnia.
To distract yourself from your worries take up a hobby or indulge yourself in activities, which will relieve your stress and will help you to overcome your stress related sleep disorder. Experiment with your bedroom noise and temperature level to find what is best for you. Taking a warm bath an hour or two before bedtime increases deep stages of sleep. Sleep on suitable bed, try to ease yourself in the bed. Repaint your bedroom with colours, which gives calming effect, will calm your nerves and slow muscular response such as violet and other purple shades and pink.