Finally, don't include more than one variable on a graph or it gets confusing. Older students should give some statistical analysis of their data, such as standard deviation, anova or t-test. Have print large enough to read from a distance. Be sure that you understand all the terms and acronyms you present. Think about future experiments and how you could expand on a project.
Many students do science fair projects in consecutive years.
You should think about expanding and significantly changing your project, not just repeating the same project. Dr. William Knott, Chief Scientist.