Drop caffeine after noon, quite alcohol/cig/weed/screens anywhere close to bed time, keep evening meals small and low in carbs/sugar to avoid an insulin spike, wait at least 3 hours before hitting bed after a meal, more is better. Go to bed at roughly the same time every day, make sure your room is as dark as can be, make sure it's not warmer than 20c, exercise so that you're physically tired at the end of the day, only use your bedroom for sleep