Design is about problem solving. A exercise you can try is to give yourself a simple problem before starting the design. For example, instead of just drawing a vehicle or character, ask yourself, what problem does it solve?
In the homework assignments below, FZD students (term 2) have to design a vehicle that can take you from point A to B, during some type of outbreak or disaster (disease, zombie, bugs, cold, hot, etc.). The vehicles must stay somewhat grounded and real world-ish (no spaceships), and provide simple defence and shelter.
This simple problem resulted in a variety of solutions. A great way to gain design experience.
For more examples, please visit FZDSCHOOL.COM
Somewhat related projects.