Create profiles on social media websites like facebook, twitter, Google+, myspace, Digg, stumbleupon, reddit, pinterest and interact with more peoples there. Find peoples of your niche on these social sites and share your products and services there.
Understanding nature, Hands on experience with live campaigns or promotions, Analytical skills, planning capabilities. Person with these characteristics can easily be a SMO expert.
Also who has knowledge about market scenarios i.e. "What to do , Why to do and How to do " ... If one is well updated about what are the latest trends then he/she can be a social marketing expert !!