Love comes from "giving to someone." When you do altruistic acts of kindness, you are giving the other person part of yourself. You will therefore feel love for the recipient of your acts of kindness - because you will find yourself included in the other person and you will identify with him. Just as you love yourself, so too will you love the other person.
The ultimate level to strive for is that even if someone wrongs you, you will view it the same as if someone's right hand accidentally cut their own left hand. Of course while you will try to prevent this from happening, you will not take revenge on your own hand!!
The degree of love as you have for yourself is the degree of love we should have for others.
Today, think of a specific person who would gain greatly from your being more giving. (If you can't think of anyone, that person might be you...)
(see Talmud - Yerushalmi Nedorim 9:4; Rabbi Eliyahu Eliezer Dessler - Michtav MaiEliyahu, vol.3, pp.89-90)