There is a lot to say for having conversations with possible users, it helps to have some "visual aids" such as a low fidelity mockup, printed-out screenshots, etc.
My current "side project" is that I create "three-sided cards". These stand alone or can be put together to make constellations like
whenever I show people the cards and let people interact with them I learn something. The cards are so good at this I am thinking about making a psychological profiling tool based on them. (One thing I've learned is that HN users want to see a manifesto for the cards, but that's been slow coming.)