I've found that it's very helpful to stop using smartphones and tablets at least one hour before going to bed. I've heard that the blue light emitted by those devices communicates to special cells behind our eyeballs that it's morning. I also love taking one 2.5 mg melatonin lozenge made by Source Naturals that I dissolve under my tongue about an hour or so before I go to sleep. Not all melatonin I've tried has been effective, but this particular product is fantastic. Relatives that I've shared the product with have loved it and found it very effective. You can find it at Whole Foods or Amazon.
RE: Sleep Debt as a cause of unnecessary stress and how to increase sleep quality