Stay focused on you
You should stay focused and on-task regardless of politics, rumor mills or non-productttive maneuvers. Confidence emerges from time-honored good work combined with great attitude.
Identify your strengths and capitalize on them
One of the best ways to build confidence is to get clear on your strengths and find ways to integrate those strengths into what you do every day. When you lead from your strengths, you’re engagedand energized. You’re self-assured.
Identify weakness and work on them
If there are weaknesses that are affecting your confidence. Make a plan to reduce or eliminate them. You shouldn’t be obsess over these things, but by addressing your weakness and making a diligent effort to overcome them can help boost confidence.
Believe in yourself
This may be much easier said than done, but try to tell yourself “I can do this”, and believe that you can. It has been proven that by saying 3 affirmations to yourself each night before going to bed – telling yourself 3 things that you like about yourself or 3 things that went well that day will help boost your confidence.
Acknowledge that your confidence may be threatened at times
It is important to know that this is going to happen, if you are on the receiving end of a mean comment that shakes your confidence, give yourself 24 to 48 hours to recover before responding or making any important decisions.
Seek encouragement from others
Ask people you respect what they think are your 3 greatest strengths, then find ways to use those strengths. Sometimes other people see more talent in us than we recognize in ourselves
Referenced from: http://www.forbes.com/sites/jacquelynsmith/2012/03/06/how-to-be-more-confident-at-work/