We have all seen it. Women who are equally qualified as men can end up playing supporting roles in organizations while men steadily advance in their careers. It doesn’t have to be this way. With these five tips, women can boost their confidence at work and increase their opportunities for success.

Do your homework. Confidence comes from knowledge. When you know the subject matter well, you will be at ease discussing it. People will see you as the expert on certain subjects and you will earn their respect.

Be assertive. This means self-assured. It does not mean rude or condescending. In fact, that is strongly discouraged. Instead, display calm under pressure while standing firm. This conveys a sense of inner strength and demonstrates that you are qualified to handle anything that comes your way.

Adjust your body language. Social psychologist Amy Cuddy explains in a TED Talk that body language says a great deal about us. Nonverbal communication can influence people so choose the postures that demonstrate power. Don’t diminish your stature by hunching over or signal that you are closed off by standing with your arms crossed. Be open and take up space to show others that you have confidence in yourself and your abilities. Just the simple act of changing your posture can change how you feel.

Be proactive. Sign up for projects that interest you. Don’t wait for someone else to take control. Tell your supervisor that you are ready to take on the special project or offer to lead a team.

Dress for success. Wear clothes that convey a sense of authority. Remember the saying, “Dress for the job you want.” Choose clothes that are stylish and that fit well. You can’t go wrong with a suit. After all, men have been wearing them for years. And stay away from silly passing fads. Classic good taste never goes out of style. When you look good, you feel good and that boosts confidence.