Diagram air, light, sound, humidity…
Human scale …jump to a human outline and the forces around them. Test design ideas. Hear are some interesting image by Renzo Piano.
Some folks asked about hand sketched partis. Renzo Piano Workshop does some great ones! See below.
They are probably redrawn over and over. RATHER than scribbling lines on top of each other you can see that each line is intentional! (some of these are probably last drawn over a hard-lined and scaled computer model 2d output – they are way too neat!)
Think about what you will draw – see it in your mind – burn it into your mind and the paper in your mind – then get it on paper quickly (not changing things).
You can repeat that. But changing your mind on paper – its not so good.