Light in the morning, dark at night
The cheapest sleep tool is already outside your window.
Your body clock is mostly a light clock.
Morning
Get outdoor light within an hour of waking, even for five minutes. Cloudy counts. A window helps; a sidewalk is better.
Night
An hour before bed, make the room dimmer than you think you need. Overhead lights are for daytime. Lamps are for landing.
You can still watch something. Just make the room look like evening, not like a store.