I've long been a student of author and therapist Louise Hay. If you're not familiar with her work in particular, just know that she was basically the founding pioneer of the self-help-book genre and industry. Folks like Dr. Wayne Dyer and Tony Robbins and Dr. Phil wouldn't really exist if not for Hay (but please don't hold that against her!).
Anyhow, one of the self-love-building self-therapies for which Louise is the best known is her system of positive affirmations -- positive statements you make to yourself as though they are true, to heal and reverse the negative messages so many of us communicate during our self-talk.