One of the best exercises (in fun) I've ever done for the last almost 10 years is SHAPEDOODLES. I take a brightly coloured marker, make a random shape and then give my brain FREE REIGN over what it wants to do next. Everything goes, i listen deftly to anything or any shape my brain wants to draw. This piece is an example of exactly what happens!!
9x12 - India ink & copic marker on watercolour paper