Warm up your face muscles by chewing in a highly exaggerated way. Do shoulder and neck rolls. Imagine that you're eye level with a clock. All of these exercises serve to warm you up and relax you. Those exaggerated movements make it easier for your movements to flow more naturally.
Preparation is a key element to making a solid presentation.
Here are a few tips that will help you make an effective presentation. It's wasting too much of those precious 30 seconds. Opening a speech with a joke or funny story is the conventional wisdom. Does it support your topic or its key points. A humorous story, an inspirational vignette, which relate to your topic or audience, are sure ways to get an audience's attention.