In chapter 2, Shri Krishna explained that the ultimate spiritual goal is the elimination of our vaasanaas. In chapter 3, he provides the technique of karmayoga which is the first step that all of us have to take in order to begin the process of elimination of vaasanaas.
First, he stressed the need to convince ourselves that we have to act. We simply cannot think that we can eliminate vaasanaas by not acting. Once we have convinced that we have to act, we have to adopt the attitude of karmayoga so that further actions do not cause bondage. The attitude of karmayoga comprises five aspects of knowledge or buddhi that we need to maintain while performing any action:
1. Samatva Buddhi : We need remain calm but alert in all situations. As the earlier chapter explained, situations are transient, they come and go. Having understood that they are transient, we should not get overly excited or agitated with each new situation.
2. Svadharma Buddhi : We should conduct self-analysis to understand where our strongest desires lie, and then deploy those desires in the service of a higher ideal. 
3. Samarpana Buddhi : We should always dedicate all our actions to something that is higher than us. We should remember that the entire universe is operating in a spirit of yajma. Whatever we own is material that is in the service of the yajna, it is not ours.
4. Asanga Buddhi : We should constantly assess whether we are attached to any material object, person, emotion, position or action. In other words, we should analyze our relationship with those things to understand whether we give so much importance to a thing that we cannot do without it. We should also remember that everything is the gunaas acting on the gunaas. Therefore, we should work with no expectation of the future, and no burden of the past.
5. Prasaada Buddhi : While we perform actions, we should not keep an eye on the result. We should accept every result as a “prasaada”. If we get attached to one type of result, whether it be positive or negative, the opposite or the complement of that result will torture us and bind us.