If you have chosen to do a performance, then you likely have a dramatic flair. But for History Day, you cannot rely on fancy costumes or elaborate backdrops to make your performance great.

Performances

1. Your script should be as realistic as possible. Time travel, speaking from beyond the grave, statues coming to life, and modern students conversing with long-dead historical figures do not lend an academic air to your performance.
2. Analysis should be the focus of your script. Long reenactments of historical events or reciting a long list of facts may be historically accurate, but they don't offer your analysis on your subject. We don't want a biography, and we don't want to see a play-by-play of your battle/court case/coronation.
3. Use characters wisely. Choose characters that have a logical reason for speaking about your subject. If you need to, you can create a "composite" character that is based on a combination of several others from your research. Narrators can be used, but sparingly. 
4. Don't change scenes too much. The audience only has ten minutes to understand your topic, and if you are constantly changing scenes and characters, it can get very confusing. Three changes of scenery/characters is a good maximum.
5. Use primary sources in your script. What better way to provide words and perspectives of the time than to read from excerpts of primary sources!
6. Costumes, props and scenery should be appropriate. Be as accurate as possible with your costumes, without going overboard and spending lots of money. Props and scenery should be useful, and shouldn't take away from your words. Sometimes, scenery is not necessary at all. Let your words tell the story!