This can become very complicated and professional if you choose, or it can be kept very simple. This will be determined by availability of materials and expertise, as well as the audience. It also enhances student confidence. The amount of practice and polish will depend on the purpose or audience. Prepare students emotionally for this.
Some audiences are more difficult than others - especially peer audiences.
This will take care of stage fright for many students. Students should be aware of their intended audience from the beginning of the project. Debriefing is especially necessary if the dance was presented to a large audience. Many middle years teachers are concerned that their students will not participate willingly in a dance project, especially the boys. I have found that boys need to choose their movements so that they are comfortable.