What do you do when you feel creatively blocked or stuck?

At that moment the loud approaching sound of a motor-car was heard in the drive. From this chariot there stepped swiftly and lightly none other than the gifted wife of Sir John Lavery. 'Painting! But what are you hesitating about? Let me have a brush—the big one.' Splash into the turpentine, wallop into the blue and the white, frantic flourish on the palette—clean no longer—and then several large, fierce strokes and slashes of blue on the absolutely cowering canvas. Anyone could see that it could not hit back. No evil fate avenged the jaunty violence. The canvas grinned in helplessness before me. The spell was broken. The sickly inhibitions rolled away. I seized the largest brush and fell upon my victim with Berserk fury. I have never felt any awe of a canvas since.