Pick and plan a safe, measurable science fair project: a testable question, hypothesis, variables, a procedure with repeat trials, a data table, the display board and judges' questions.
Structure a complete lab report around your measurements: aim, method, tables, worked calculations, error analysis, discussion and conclusion, without changing or inventing data.
Correct a myth or misconception without reinforcing it: a clear alternative explanation, the trick that makes it convincing, an analogy, verifiable consensus sources and replies to objections.
Turn a paper or its abstract into accurate popular science: what was done, what was found, what it does not mean, the limitations and an honest headline, in the format you choose.