If you're having trouble sleeping recently, it might be time to get away from your man-made, lighted devices, and enjoy the outdoors!
This is something I've definitely noticed, but now science is backing it up, too! An article in Current Biology (http://dx.doi.org/10.1016/j.cub.2013.06.039) explains that man-made light (such as your computer, smartphone, lamps at home, etc.) keep you up at night because of various effects of the light! So, when you're having trouble sleeping and you begin to browse your phone, you're actually making it worse!
One solution to this problem (which I also use) is a screen color changer for your phone and laptop. These kinds of apps filter the blue light (which has been known to be a major culprit in causing these problems) out of the light. Your phone screen appears slightly pink or orange, and you're more likely to be able to fall asleep easily at night!
However, now a better solution that I LOVE has been proven. The answer is the go camping!! It seems that, in a small sample, those that went camping for one week with no man-made lights or phones (only campfires!) had a better sleep cycle in just a few days. Their bodies seemed to sync to the solar time, meaning that they fell asleep more easily once it was dark, and woke up with the sun.
So, if you've been having trouble sleeping, go camping! Spend time outdoors. You'll be getting a lot more benefits than just better sleep, too!
If going camping isn't feasible for you, try turning off all the lights in your house when it gets dark, and adjusting to this system in a different way!