Helpful strategies:
Get up and write down everything that's on your mind. Or make a big list of those things. Then, tell your brain that there it is, on paper, so nothing will be forgotten and will everything can be picked back up tomorrow. Now, it's time for rest.
Think of a favorite memory in the real world. Like a vacation where you were swimming in the ocean and running through the waves. Or horse back riding. Anything that brought you pleasure. And replay those memories back in your mind. That will help you relax and keep your mind from over-engaging.
Get off the computer or TV or video games at least an hour before you want to fall asleep. If your mind is too stimulated before going to sleep, your brain can't just click off like a light switch. This seems to get worse as you get a little older too (not that you are.) But I find since I sleep a little more lightly than I used to I have to respect not getting my mind all worked up before I want to go to sleep.
Have a warm bath or shower - that triggers the natural cooling reaction of the body before sleep and the release of natural melatonin.
Do mind-writing: create a soothing catch phrase for your self, like "gentle relaxing night" and imagine writing it out in long-hand in your mind, while you're laying in bed. In between each time you write the phrase, count backwards from 97, and write that number out in your mind as well. So, the sequence: "gentle relaxing night" then "ninety-seven" .... "gentle relaxing night" then "ninety-six" ... etc. I've never gotten much further than somewhere in the 80's using this technique.
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Waking up in the middle of the night and not being able to fall back asleep - that's another issue. Is this happening to you, or is it mostly falling asleep in the first place, but once you are asleep, it's all good?