Every competition i attend starts before i even glove up. Watch as many fighters as you can, whether they are fighting or warming up in the corner. You can pick out their good and bad points simply by watching... their favourite techniques, are they fast or slow? Punchers or kickers? Lefty or righty? Pressure fighters or counter fighters? etc. One of them could be your first opponent, always better to be armed with the knowledge of your opponents strengths and weaknesses so you can exploit them later on. As mentioned by others above, relax when you're fighting and enjoy it. Keep moving around the area and stick to what you know works for you. Avoid anything too flashy, stick to good old basic roundhouse kicks and reverse punches if you're not too sure. The most basic techniques are the most commonly scored simply because they work.