This technique is credited to Louise Hay.
Every morning, or whenever you have a few minutes to do this, when you look in the mirror, look yourself in the eyes, address yourself by name, aloud, and say I love you.
It might feel super awkward at first.
That's ok! Keep going!
Name some things that you love about yourself.
Sometimes it might feel disingenuous.
Do it anyway.
The more you do it, the easier it gets.