I happened to put my brush on some kitchen paper - it absorbed the paint from the brush! When dry, it looked like a blue flower, so I used it and just added a few squiggles of pen.
ONE BLUE FLOWER
I CALL IT
'OUT OF THE BLUE'
Sketching can be as complicated as you want to make it. Firstly, find the idea OR you may have the subject in front of you. Next, ...