For more ideas, look on the Web for extensions other students have contributed. In any experiment you do, always think carefully about safety. Think about what might go wrong and how that can be avoided. One person in the group might be given the task of being a safety officer and asked to always think about safety. Even if you do this, everyone should be aware of hazards all the time.
Safety is everyone's business.
Reporting Keep a journal as scientists do, even when messing around. Record all your questions and observations in a bound notebook. Don't erase, just cross out errors. Write enough so someone else could reproduce your experiments. Diagrams can save lots of words and help make your ideas clear.