The first thing that came to mind for 'a penny for your thoughts' was the picture book character Henny Penny...thinking that the sky was falling after being hit in the head by an acorn.
I loved this book as a kid, so I used the original picture book illustration as inspiration.
I've never worked in Illustrator but OMG...I loved the blob tool...and funny enough, how clunky it was to use. Using the mouse and blob tool felt like I was using my left foot to illustrated this...but in a way it was liberating as I didn't get caught up in the I detail.
The technique of colour separations and layering in texture was new (to me) heaps of fun and something I'll try and use again.