Contrast is a way to highlight the most important elements of a design and add emphasis. Contrast happens when two design elements are in opposition to each other, like black and white, thick and thin, modern and traditional, large and small, close and distant etc. Contrast is what helps guide the viewer’s eyes to the most important parts of your design and helps organize the information in an easily digestible manner.
Watch this video on How to Make Dynamic Compositions. It's primarily aimed at digital design but the guy explains how to use contrast to tell your story really well.
Choose two different objects. Create 3 different designs each using both objects but contrasted in different ways so that each design tells a different story.
Add your designs, or photographs of them to your portfolio