Have you ever had a tune stuck in your head?  Often, the best solution is to find a copy of that tune, play it, sing along with it, and gradually erase it from your brain.

If you're having a grumpy day and you need to make art, maybe you should start with some good, grumpy art!  Express yourself and your deepest feelings in art, even if it's art that nobody will see.  Get those feelings out of your head!

Never try to "fake it" with art.  Art only works when it's authentic.  Instead, put your emotions into your art, and see if that helps you move beyond a case of the grumpies.

Links:
SantaFlamingo.com - The very new hub of all of my work as Aisling D'Art