When you look at the user stories of the TaskAgile applications that we just wrote, they are clear and small. But they omit important details that developers need in order to start the implementation.
In fact, user stories are only starting points for discussions on requirements. For example, when you look at a story login, you would ask questions such as, do we need to add a placeholder for each input field? Do we need to add labels for these fields? If we do, should the labels be to the right of the fields or above the fields? Different people can have different ideas about how to implement a user story.
Creating wireframes for user stories can help everybody understand what needs to be built. And you can link wireframes back to user stories which will become the pointers of implementation details.
You can use paper and pencils to create the wireframe or write them on a whiteboard. These two ways are straightforward, but not maintainable and not easy to be shared within...