It all starts from within. Only that what is within only can come out. If there is love within, that love will come out.
When you love yourself, it means you feel comfortable with yourself, your values, beliefs, words, and actions. You are not embarrassed about yourself. Instead, you love yourself. When you feel happy within through love, you start expressing that love to others. The love within now becomes external. You start spreading love to others. The whole of humanity becomes your lover. You start writing the story of your happiness.
Loving yourself isn't vanity, it is sanity.