Presentation skill rocks! Try deep breathing if you feel a sudden flow of nervousness. You will feel relaxed after three or more deep breaths. Nervousness is mostly felt at the beginning and hence tries deep breathing before starting your presentation. This helps you to calm down. Try it and notice the difference. This will surely increase your confidence and in turn your presentation skills. Practice makes a man perfect so goes the saying. This applies to almost everything even to your presentation skills. Practice and practice till you are perfect. Only practice can give you the amount of confidence, which you won't be able to gain through any other means. The more you practice the better you will know your topic and this will help you overcome your fear.  Try to break the ice between you and the audience by saying a little joke. This might sound strange, but it is a very efficient method.