The cheapest and easiest way to create a prototype or wireframe.
I use a super-practical method to create mobile wireframes on paper: picking up my cell phone and placing it with the screen facing down on an A4 sheet. Using a pencil or pen, I make an outline about three or four times. That way, I can create a mobile screen to make sketches.
The advantage of the role is that it is more agile and much easier to stimulate creativity and collaboration. Creating something of low fidelity is interesting, gets rid of the details, and creates something more conceptual in an efficient way.