a dark room, comfortable temperature, and quiet (i always use earplugs)
eating enough foods in the evening that make me feel "full" for a long enough time (e.g. enough fats and proteins). Often for me, sleep issues seem corellated with feeling hungry in the night.
sports in the morning or early afternoon, but not in the evening; stretching and meditation in the evening seem to help
no caffeine or similar substances 8 or 9 hours before sleeping
drinking warm herbal tea before going to bed, in particular e.g. with
lavender
orange blossom
lighting a candle and having just that light for a bit before going to sleep
burning palo santo
massage of the feet with lavender massage oil right before going to bed
taking magnesium in the evening an hour or two before going to bed
some journaling/free-writing in the evening to clear out thoughts
no screens (computer, phone) at least ca. 2 hours before going to bed
trying to fall asleep while listening to "rain sounds" in a loop on my headphones. This seems to be calming for me, and also seems to help block out external noises as well as internal mental chatter in my head
listening to this 30min guided sleep meditation once in bed and ready for sleep (the guy’s voice is somehow really relaxing!)
sleep medication: I sometimes use "Benocten" to help with falling asleep. I have the impression my sleep quality is less than normal if I use it, but sometimes this is preferable to no sleep. The next day I’m sometimes a bit groggy from it I think. With other sleep medication that I’ve tried I feel more groggy though and they also often didn’t work to make me sleep for sure. So I’ve opted to not use sleep medication, except Benocten once in a while.