It's never the same thing that works every night, but I do always need black out curtains and a brown noise sound playing and I need to put my phone on do not disturb and detox mode so that I mentally check off from using it. I also have a weighted blanket that I use sometimes, and I recently found a specific sleep meditation that helps my body and mind calm (the one I use is in the practice of "yoga nidra" -- kind of like a body scan).
As far as supplements, melatonin on its own has never helped me. I got super familiar with the sleep aid isle of the drug store, tried a variety of things, and paid attention to the ingredients in things that worked vs. didn't work. I kept finding 'l-theanine' in the ones that worked, as well as "ashwagandha" in a couple, so I started just buying those supplements seperately at a grocery store near me that has them. Now I usually only take these when I'm over-stressed or having panic or anxiety attacks, just because that is what they both help best with. If I've been stressed or restless all day or close to bed, I'll take these before I lay down.
I also started getting a sleep tincture from the same grocery store (Fresh Thyme) that has valerian root, hops, skullcap, passion flower, chamomile, and California poppy in it, and it is by far my favorite thing to take to help me sleep. It helps the most consistently. I take it in some tea, and sometimes take kava (also in tincture form) with it. I've also started taking CBN (a cannabinoid) at times, which at first had a physical effect on me like nothing else -- very noticeably making my body heavier and slower -- but it hasn't been feeling effective lately.