Don't be bashful! If you want comments, give comments. You don't need to be an expert photographer to express your opinion about the work of others. You don't need to go into great depth. A simple remark about cropping, composition, color, subject matter, etc. can be of just as much help to a budding photographer as an in-depth critique.
One compositional trick is to include in your photograph something very close in the foreground, something in the middle ground, and something way off in the background. This layering forces your viewer to spend more time looking at your image and makes the composition more exciting. An excellent example of this would be a photograph with wildflowers in the foreground, trees or a rock formation in the middle ground, and a lake or mountains in the distant background. For this assignment, I want you to shoot a scene with an object 6 feet away from you, an object 20 feet away, and an object 40 feet away or at infinity. Get all three objects in focus and make it visually interesting. You need to shoot at a small aperture, such as f/22, or use the hyperfocal distance focusing technique to sharpen all three objects.