I am a firm believer in Karma, which is why I will never do something to someone that I do not want done to me. Though, I do try to live a positive life and get along with all my fellow humans, the end result is not always that pretty. Having said that, I think it is important for us to at least make an attempt to live our life in the best way possible. Meaning, if you went to bed tonight and you can lay your head down knowing that you didn't hurt anyone or tried to cause a disturbance in their life, you did good.
Karma doesn't seem to like me very much in general, but it doesn't mean that it cannot work wonders for you. Just remember the idea of cause and effect. Other than that, best of luck to you.