I second @punkarsenic I took classes on comics where a lot of our first assignments were pciking movies we really liked and taking screenshots from them and adding the dialogue that followed as well. It helps you figure out what actions deserve more focus over others and how to go about placing dialogue so that it's readable.
edit: Here's an example of one of the assignments. I did Skyfall (a James Bond movie) It's maybe five minutes of the opening scene. We then had to redraw it but I don't want to bog down this post. If you're interested though, I can upload them as well.