Digital painting relies on your ability to comfortably wield the Brush Tool. Keyboard shortcuts are a huge part of that, and committing them to memory is an important step in your learning. This video proposes a 'maze' drill for you to hone your brush tool chops. It may seem a bit unusual, but it's not all that different from an athlete running through an obstacle course to improve their agility! Most importantly, have fun with this! And make sure to download the brush maze drill here.  And if you want a refresher on the brush tool and its hidden features, check out this digital painting 101 video