Apply random lines, scribbles and splashes. And aim to move your whole arm, perhaps even your whole body, to help you loosen up. Water-reactive crayons or pens, or the best watercolour pencils are ...

Ethan Murrow recently spent two weeks drawing a massive mural inside the ... surrounded by water—using only Sharpie pens. “It’s a slow, slow process of building up many, many marks ...