If might be helpful to set aside notions of "good" and "bad" karma because this distinction just creates confusion and reinforces misconceptions. Instead, think of skillful and unskillful actions. When remembering that actions include behavior and also mental actions(thoughts, feelings, and images that you intentionally engage with and nurture), you will discover that certain actions lead to beneficial results, that is, you feel good and others around you feel good. If you walk down the street smiling, you will feel good and others around you will feel good. This is acting skillfully("good karma"). You will also discover that certain other actions lead to harmful results, that is, you feet bad and others around you feel bad. If you yell and criticize and kick the dog, you will be lost in feeling bad, later experience regret, and adversely impact those around you. This is acting unskillfully("bad karma").Acting from the three poisons of greed, hatred, and delusion is unskillful, while acting from their opposites-generosity, kindness, and wisdom- is skillful.