This tiny little excerpt from a sutta might make a wonderful teaching to memorize and say before you meditate, go to sleep, or get on an airplane.
A wise person who is truly free
Will always sleep well.
They are not corrupted by lust.
Their desires are calmed.
All attachments are severed,
The heart is freed from sorrow.
The peaceful person sleeps with ease,
Having attained perfect tranquility
-Hatthaka Sutta (AN 3.35)