With your thoughts and feelings you create and perceive the world that surrounds you. According to what your thoughts are, thus will be your feelings and emotions, your attitude and your actions. This process usually happens rapidly, and you are not usually aware that it is taking place. As this process repeats itself often, it is easy for a set of habits to be created.
The effort lies in slowing down this process in the mind, as if you were watching television in slow motion. On the screen of your consciousness you can use meditation as a method to slow down this process and be aware of what you are feeling and thinking, how you are acting and being aware of the result that you obtain.