Tools for understanding the people you are building for, and turning what you learn into something you can actually build.
Product work moves through a rough sequence: understand who you are building for, understand their experience, then decide what to make. These templates line up with that sequence, and they are most useful when you use them in order rather than picking one in isolation.
A user persona turns a segment into a specific person with goals and frustrations, which makes design arguments concrete. Instead of debating what users want in the abstract, you are asking whether a particular person would find this useful. An empathy map goes a level deeper on one persona, separating what they say and do from what they think and feel, and that gap is usually where the interesting problems live.
Once you understand the person, a customer journey map lays out their experience end to end, stage by stage, including the parts that happen outside your product. Friction rarely sits where teams assume. A user story map then turns all of that into something buildable, arranging stories along the journey so you can slice a release horizontally and still ship something coherent.
The design thinking template holds the whole five-stage process, which is helpful when you are running a workshop and want the structure visible on the wall. A sitemap is the most concrete of the group, laying out pages and hierarchy before anyone opens a design tool.
Working visually helps here more than in most disciplines, because research synthesis is fundamentally about moving things around until patterns appear. Group notes, regroup them, and share the result with people who were not in the room.