Just as with leaders, motivation is the most important single factor. If you focus on the goals to be achieved and are motivated, you will a good follower and, perhaps, even a good leader. Second in this list are such characteristics are reliability and loyalty. These are also important for leaders. Very few of us have all of best characteristics to be a good follower to the limit, but the most effective follower and leaders regardless of which role will have most of them well developed.
Improvement is limitless.
Remember, changes in the personality traits take years of consistent work. We can and should start today, but don't expect instantaneous results. An outgoing style - the ability and enjoyment of working with other people in a team is a useful skill. A sincere liking and respect for other people is a wonderful asset. Being well liked will certainly help in working in teams or any other social situation.