I agree with kev-kun, your cinematic and visual techniques will most likely comprise of the majority of the questions. As well as the visual elements and mis-en-scene you should also make sure you understand how sound can work as a technique, especially knowing the difference between diegetic and non-diegetic sound and how each are important in creating meaning. In terms of practicing, you can only go so far as to learn techniques and how they work and then practice on scenes from various different films.
In the actual test, one of the easiest ways to convey what you are trying to say to the marker is to remember. Identify a technique - Give an example of how it is used - Explain how the technique works to shape the responders understanding of the text / the texts meaning. If you constantly always do those three things when writing out answers you will be fine.
