From HMUN 2013, bestdelegate.com

Public speaking is one of the most important skills you will use and hone as a Model UN delegate. You will need to convey your member state’s positions, help build consensus, and formulate resolutions.

You will have numerous opportunities to speak in your Committee during GWCIA. The Chair will call on delegates who would like make formal speeches during debate. During caucusing, you will have an opportunity to speak informally to delegates in your committee, but it is still important to keep the principles of effective public speaking in mind.

Although speaking is an important part of any Model UN simulation, many delegates fear speaking in front of a large group. The best way to cope with these fears is to be well-prepared. You should research as much as possible about your country and the issues relevant to your Committee. If you come to the Conference prepared and comfortable explaining your country’s position, you will be eager to speak in Committee and project confidence.

More information on how to make an opening speech, make a speech during debate, and overall public speaking tips can be found here.