Design Thinking has a bias towards action – that means if you have any uncertainties about what you are trying to achieve, your best bet is to just make something. Creating a prototype will help you to think about your idea in a concrete manner, and potentially allow you to gain insights into ways you can improve your idea.
Prototyping is all about speed; the longer you spend building your prototype, the more emotionally attached you can get to your idea, thus hampering your ability to objectively judge its merits.
All prototypes should have a central issue they are testing. Do not lose sight of that issue, but be open to other lessons you could learn through your tests.
Test the prototype against your expected behaviours and user needs. Then, learn from the gaps in expectations and realities, and improve your ideas.
LEGO or other crafts to make a mock-up
Post-its
If it’s an app, you can create a “flick book” of a core feature of the idea.
If it’s an interaction, create a storyboard and through feedback, swap and change the order of interactions to find what resonates most with users.
Slide with animations (to demonstrate how something digital like an app might work). Here is an example of an idea and prototype for a Running Accountability App (by @andymakes_)
Robots: Edison,
Website