It seems there are two kinds of people who design their own work.
Those with a non science mathematical bent use sketchbooks, make samples, try ideas out.
Those with a science/mathematical bent, do all (or nearly all) of the design work in their head.
I've just listened to a program on Einstein and his violin. Apparently he particularly like Mozart who arranged and composed the whole composition in his head before committing it to paper. He also was fond of Bach (I have no idea of his composition method). Einstein used his violin playing to work out problems in his head and/or to clear his head and focus.
I suppose there are designers out there who do a mixture of both.
Random thoughts for a Monday morning. I still haven't got my quilting back on track though my brain is designing away at a rate of knots. It will come. Perhaps now Fliss is back at university and DH is back at work it will come back to me.
And the kittens on a lazy Sunday afternoon.