Find a place to practice
Of course, practice makes perfect. Find a place where you can interact with other people and can speak in groups without necessarily having to stand in front of the group in a formal setting. Try churches, talk shows and other social gatherings, even a book club. Any group that welcomes the exchange of ideas and opinions in a very informal setting will help you to enhance your confidence gradually.
Involve yourself in presentation activities
If you are a student then you should participate in debates and other related activities. You can find some societies to join or attend seminars in order to beef-up presentation skills. As you start to speak in front of small groups more frequently you will begin to get feedback from those around you, which will help you to learn the dos and don'ts, as well as giving you confidence when you hear how well you did.
Get online help
An easy and quick way to impress your audience and boost your confidence is to use slides. You can get ready to use slides online.
Don't lose your control while delivering your presentation. Even if you forget something just continue on as naturally and calmly as possible. This will make a good impression on the audience. Don't rush; take your time and pace yourself. A question and answer portion will help to fill in time if you need it, as well as get you interacting more personally which can help you to relax and be yourself.
Get feed back
After your presentation always ask your audience how they liked your presentation. Did they understand everything clearly? Could they hear you well? Do they have any suggestions for improvements?