What sleep hygiene changes helped with poor sleep and erratic bedtimes?

[Timothy78]

My sleep has been terrible for months; I have trouble falling asleep, wake up multiple times during the night, and never feel rested, which is starting to seriously impact my focus at work. I know I need to improve my sleep hygiene, but my current habits are a mess—I use my phone in bed, my bedtime is erratic, and I often have caffeine too late in the day. For those who have successfully turned their sleep around, what were the most impactful changes you made to your evening routine and bedroom environment? How long did it take to see real improvement, and did you find that strict consistency was absolutely necessary, or were there one or two key factors that made the biggest difference?