It starts with making a choice of allowing yourself to love him or her. It starts with making an emotional and mental choice to risk the weakest part of your soul and that's your heart, where all decisions of life,love and belief are taken. Loving yourself begins in starting to love your wounds,failures, disappointments,hurt,pain, insecurities and unbelief.
When you know how to love yourself in a patient, peaceful and hopeful manner you can build yourself up mentally, emotionally, physically and spiritually. You first disappoint yourself,hurt yourself to know that in the mistake you find yourself and you know yourself. You know yourself then you can love another, understand another in a way they are used to or in a way they want to be loved because then you know that loving someone in a way they aren't used puts you at a disadvantage because you lose someone you love.
So love yourself in a way you know best how so you can do the same for another because you can't give someone something you don't have.