1st Step: Start with the film title.

2nd Step: Write the type of film.

3rd Step: Explain the film´s story, a short summary of about four-five lines.

4th Step: Give your opinion of the theme. 

5th Step: Write clear paragraphs and sentences. Use phrases like:

First of all, Firstly, In addition, also and To Sum up, In conclusion, to start each paragraph.

And express your opinion using: I think, I believe, in my opinion, I agree/disagree that...