Women love, love, love confident men. If you low on self-confidence, click here. Same with low self-esteem - click here.
Mentally tell yourself that you are a great and confident guy.
Be optimistic and positive.
Approach a woman without the fear of rejection. If you are rejected then it's not a problem. It doesn't have to hurt you or diminish your confidence. Anyway there is nothing you can do to change the fact so get over it - fast.