In my social impact design practice, I create low- and mid-fidelity prototypes to generate iterative feedback from communities and end users.
The above are all prototypes I created for a project funded by the American Heart Association to improve the healing journey for stroke survivors. I use a wide variety of mediums when I make prototypes, from low fidelity creations quickly pieced together from recycled materials, to higher fidelity designs laid out in InDesign. Not pictured are a set of cards I created for a card sort activity, as well as a higher fidelity prototype of an app–a clickable simulation the user interface through Keynote.
I decide which medium to use when creating prototypes based on what will best facilitate useful feedback to incorporate into future iterations.