Drawing teacher's critique

The drawings that I made in my sketch book are not satisfying to me. Thinking that my drawing skills are lacking, I have tried meeting with a drawing teacher. The review of what I've drawn is that although I may have a good idea, I need to make some decisions. What is the best placement of the characters to express the things I want to say? How can I use props to emphasize the story? There are a lot of elements I want to include, so how can I make the best use of the space I have available? I need to compose the story before I can record the image.