As we move from exercises to creating designs, subject matter becomes important. Here we see (attached, or to the left, if you are reading this on my website) student work from my courses over the years (black and white and color, depending on the assignment) that includes creating an avatar, invented perspective, invented forms, absence and presence, equations, etc.
What you choose to do for the equal black and white, formal, informal, value, final project assignments is up to you are far as subject matter. Don't be constrained by thinking things have to be representational. Art history and contemporary design are full of abstract, non-objective designs and patterns as well as illustrative illusions of representational space. Your own influences may be graphic novels, anime, second life, or more traditional themes of still life and portraiture. Whatever you choose, let us know when you post your work your influences, design-likes, dislikes, art and design heros and anti-heros that may have affected the work stylistically. Set the stage for us viewing the work. Create context for understanding the image, culturally, historically. And include descriptions of your brainstorming, technical hurdles, design process. If this sounds hard, then get ideas by reading some of the student posts I included on my site along with the student work.
The file (partially shown here) is about 480k. It may take a few seconds to open.