A variety of suggestions....
I'm a bit odd in that my favorite labradorite stone works both in daytime for focus and at night for sleep. I suspect because it calms my emotions to some extent, it manages both effects. But it may simply be that it's become something of a talisman--I ascribe behaviors like these to it, therefore my mind triggers them to occur when I'm in contact with the stone. All I know is, when I can't sleep, I bring it into the bed. I may hold it, or stash it under my pillow.
How comfortable is your bed? I added a 3" memory foam pad to mine recently, and after a couple of days of getting used it it, holy cow. I'm having a lot less trouble sleeping. (And less joint pain when I wake up.)
If you can't block light from the room, use a good sleeping mask. My personal favorite is from a company called Bucky; unlike the dainty satin ones, theirs have additional padding to block out light from beneath the nose area, and stand out far enough from your face that you can open your eyes completely without touching the mask. Which is silly, because of course, you can't see anything when you do that!
White noise can be helpful. So can earplugs. Guided meditation is also useful for some people. I'm a writer with a rampant case of ADHD and head full of characters that like to chat; meditation to them was never easy, and to my characters, it mostly signal my brain is now available; they take it as a sign to talk more. Which is not good for sleep! Instead, I'll spin myself a quiet story with a familiar character-friend, a tale that meanders around aimlessly, doesn't touch on vibrant emotions or situations, and is just boring enough to fall asleep to. (If an idea worth writing about or a forgotten task *does* occur to me, I do add it to the notebook on my phone....and then PUT THE PHONE DOWN AGAIN. That part is key, or I'll be up all night.)
On getting onto AT when you wake up: you don't need me to tell you how bad an idea this is. Put the phones, tablets, laptops, etc. away from the bed if you have to. If you can't, at least make sure you're running f.lux on them to mitigate the effects of blue light on your sleep. Blue light is highly stimulating, and you'll stay awake longer when exposed to it! (F.lux cannot be run on stock Apple iphones and ipads; they need to be jailbroken to run this. Please send feedback to Apple; this functionality should have been built into iOS years ago.)
Sleep studies are a necessary fact of life for many. It's always important to rule out issues like sleep apnea.
Herbally--valerian is the only "traditional" herb that seems to work on me. Others, like kava kava, have no effect. As most prescription sedatives are also a problem (my metabolism is unusually efficient at getting rid of them, to the point that anesthesia is an issue for medical procedures!), it doesn't surprise me that most herbs don't work either. Other supplements, like magnesium, have some small sedating effect that works better IF I also take valerian. So I do use that regularly.
If it's medically legal in your area, a high CBD product can make a huge difference. As these are derived from cannabinoids found in marijuana, they're not readily obtained for many, and if you're an active dreamer or prone to nightmares, it may be best to use this very sparingly. But they can work for severe insomnia, and high CBD-low THC supplements can be useful with a number of other health issues that may be contributing to sleep issues. Because they're created with very little of the THC component, there's no "high" associated with this substance. (Capsules and tincture of this stuff probably kept my husband alive long enough for chemo to do something about his cancer, by controlling his nausea enough to eat and his anxiety/panic enough to let him sleep. Nothing else medically prescribed was working on either of these issues, even in combination. And unlike most drugs, it actually does have a sedating effect on me.)
Lying on your stomach can do a real number on your neck if you do it regularly. The subsequent migraines aren't worth it. I grew up doing it, and have permanent neck & upper back issues as a result. Strongly not recommended. Finding the right bed and pillow are a better idea.
While not eating before bed is probably a good idea, if you're like me with irregular eating schedules to match your irregular sleep schedule, you may HAVE to have a snack to quiet your stomach some nights. Look online for lists of sedating foods.
That's all that's coming to mind at the moment, but I'll be back when I figure out what I've forgotten due to lack of sleep! LOL