Gee Tom.....good question but I can't answer it. I mean I want to try...but jaysus its so broad.
You might as well ask me to sum up the creative process in a constantly shifting life and learning tableau.
Inspiration comes from experience and exposure to all the stimuli that have been absorbed prior to the moment one is inspired.
I'm old enough to chronical how the design process has changed in me.
When I was young I had raw creative energy....but not enough experience.
I'd compensate by drawing furiously....in a compulsion to get things on paper where I could see it, move it around, and make it something tangible.
I'd dash all over the world looking, observing everything....others work, terrain, weather, water, nature, cultures....it didn't make any difference in my quest to fill my brain with most anything. I figured a while back that I had slept over two years of my life in the front seat of various Ford Pickup trucks.
I remember once sitting for most of a day at 15,000', perched above the fields that lie outside the Teng Boche Monastery....all the while watching 300 Yaks and porters snake their way in and fil up the plain below....it was a French Everest Expedition, and I was thinking Jeysus...it takes all this stuff to climb a mountain? It was only a little later that Messner blitz/climbed Everest solo...with no oxygen...which impressed me.
I'm older now and I guess I don't carry as much superfluous baggage.
I internalize and am able to roll it around in my head better, sans all that external clap trap.
Now I'm content to analyze the sites various givens and just give it a go.
Design on the fly, inspired by all that's proceeded me....the inspiration being a constantly evolving process.
I doubt any of this begins to answer your question.
BTW....thanks for allowing me the opportunity to look like an even bigger idiot than I can appear at times.
Namaste.