I agree with the breathing advice for relaxing and slowing the heart rate.

In the world there are different sleepers, and no two people fall asleep in the same way. And no two people learn to lucid dream in the same way.
As such, you should not compare your dreaming progress so much to others.

If you are having difficulty to falling asleep,
try and get a early night to bed, and make yourself warm & comfortable.

Also for some researchers - a lack of vitamin B6 causes some people to have difficulty remembering dreams.