Design Thinking is a simple approach to problem solving. There are 5 steps in this process.
Empathize: This step asks you think about WHO you are solving a problem for. What are their needs and how can you best serve them?
Define: What is the problem exactly?
Ideate: This is the time to come up with as many ideas to solve the problem as you can. Celebrate the power of possibility and don't be tied down by limits.
Prototype: This is a potential solution. It can be in the form of a drawing, or a model, or the first round of actually building your solution.
Test: Use your prototype and get feedback to make your idea better.
A reminder: The design thinking process is meant to be repeated and you likely won't have the ultimate solution in your first round.