Sapphire-
If you are talking about qualities that are not really possible for you to acquire, such as looks, personality, etc., then perhaps what you really need to work on is not overcoming jealousy but rather recognizing the value of you. I don’t know you from a hole in the wall but I am sure that you are a unique, special individual, who just needs to refocus a little and recognize his/her(?) own value. There are plenty of books on this subject, because it is something a lot of people tend to lose perspective on. Rabbi A. J. Twerski’s books are very good, and I’m sure others here have more recommendations.