Don't do anything exciting 2 hours before you go to sleep. Ex. bedtime at midnight; do nothing exciting from 10pm on. That means no video games, no favorite tv shows, no cooking/cleaning etc. You can watch boring TV shows, stuff that you're not interested in, some LIGHT hw, etc. This is down time, time for you to just chill, relax, and do nothing. Just get into that mindspace, just relax.
Once you feel a little bit sleepy, keep it up, close your eyes slowly hear and there, tell yourself, you feel sleepy. Go to the bedroom, but do that slow walk, like you're so tired, you are just to get into that bed. Get into bed, your body is heavy and you just fall into bed. Your body sinks in. Mhmm, so warm, so comfortable, so cozy... ahh, so relaxing. Close your eyes, and give yourself a small smile. Now start to dream, think of a fantasy (not a sexual one), hmm, dream of a perfect life, what does that look like for you? Dream job, car, spending, relationships, follow your thoughts and dream, dream big till you drift off....
If you're not asleep in 30 minutes, get out of bed, turn on the TV, and start over.