I think the only way to boost self esteem is to do stuff, not "think" it. If you go out and help others, volunteer or something, that makes you feel good about yourself. If you work hard at work and get a promotion or take a course and do well, that does the same. Identifying and going toward what you want in life and enjoying the process is what it's all about.

Self esteem is about self. Paying attention to what other people are doing in their lives and comparing yourself to them or putting too much weight on what others are saying about you can't help you with yourself.