I've improved my sleep quality (as measured by FitBit), by eating smaller dinners earlier, and not snacking at night. Avoiding alcohol entirely most nights. Avoiding drinking water before bed so I don't have to get up to pee

I take Webber Super Sleep (available at Costco). Has Melatonin, 5-HTP (serotonin precursor), and L-Theanine. Seems to help