Look what I found in the box with drawing tools of my children: my old McKinsey exhibit rulers! I would carry these with me 24 hours a day in the 1990s. All charts were sketched by hand before being handed over to graphics assistants who would convert them into computer visuals (first overhead slides, then PowerPoint slide shows).

The sketching by hand is a really good thing. But the limited number of available shapes restricted the creativity somewhat, all charts looked very similar as a result. See that big question mark? In case you did not know the answer (yet) :-).