You must understand that the things you resent in others are the traits you most dislike about yourself. And the things you admire about others represent the traits you most admire in yourself. For example, I stutter from time to time. And whenever I notice someone else stammering I become involuntarily filled with resentment for that person. Conversely, I admire those who are well-spoken because that's where I wish to see myself.
So in order to bring out your favorite traits, surround yourself with those who have them in abundance. And if you want to be rid of your demons, stay away from people who possess the same ones.
You can also apply this knowledge to dealing with others. When you realize that people resent their own negative traits when they see them in others, it makes it easier to understand any criticism they direct at you.
Imagine you have a friend at work who berates you for not keeping the office organized to his standards. Yet one day you ride in his car and see the floor is covered in trash and food wrappers! What happened to the organization he obsesses over? It seems hypocritical. But it isn't, once you realize he struggles with organization. He berates you because he wants to help you to be organized to!
Remember the words of Yogi Bhajan - Look at another person’s behavior toward you as a reflection of their relationship with themselves rather than a statement about your value, then you will over time cease to react at all.