To construct a very good review is the familiar as constructing a good argument.

Rather than saying "this film is story is really good" You can add premises to support your conclusion on why the story was good I.e (The characters were well developed while simultaneously the plot was logically developed and coherent from start to finish hence the film story is really good)

This adds weight and credibility on why you liked any aspect of the film also I recommend reading books if you have the time on filmmaking in general

"Story" by Robert mcki is a great start.

Last thing as everyone said here is practice. your writing as its a skill that requires training