There Is no U or X in team!
The amount of time good designers spend creating mockups is often trivial compared to the time and energy they invest into finding the best way of communicating their ideas and designs to stakeholders.
It’s because they understand how stakeholders (or clients) have to be part of the process. Including them in a way that’s helpful and doesn’t derail the project objectives is critical.
Remember, there Is no U or X in team. Check Tom Greener’s book Articulating Design Decisions and learn more about how to communicate efficiently with your stakeholders.