1. A review is not a book report.In a book report, you’re letting the teacher know you read the whole book, so you have to tell the
whole story. In a review, you’re telling the reader whether they ought to read this book, or go to this
movie, or buy this product.
Don’t tell everything that happened -- just enough so the reader has a sense of what it is about and what it is like. Especially, don’t give away surprises, endings and other parts the reader will enjoy discovering!
That’s called a “spoiler” because it spoils the experience for the reader. Usually, you won't tell what happens after the first third of the book or movie, though you might give a hint like "But he's in for a surprise!" or "Her troubles are only beginning."
2. Do your homework.If a book is the third in a series, you should be familiar with the other two. If a movie is based on a popular book, you should be familiar with the book so you can tell the reader how much it is the same, and how much it has been changed.
3. Tell us what you’re talking about!The name of the book or movie belongs somewhere in the first three sentences. Don’t keep us guessing, and don’t think putting it in your headline does the job.
4. Use comparisons.If a film contains a lot of magic, is it like a Harry Potter movie? Or is it more like “Princess Bride?”
If it’s part of a series, is it like the other books or films in that series? How is it different? Try to compare it to things your readers are probably familiar with.