Whether your discipline is music performance or building electronic circuits, or whatever, you can probably think back to a time when practice was fun. Unfortunately, undertaking serious study has a way of killing a lot of the wonder from earlier experiences in the craft, replacing it with frustration and disappointment.
Despite the seriousness of pursuing perfection, we must keep that wide-eyed little kid from our past alive! In reality, the version of ourselves that loves to play is just another side of the Practice Monster. If we keep the beast well fed and let him run free once in awhile, he will be less likely to misbehave. The monster is a tremendous source of energy, and it can be used for help, or for harm.
Enter rampage mode. Pick something that you love to do, something that is not necessarily "easy," but something that you have learned well and enjoy. Have at it! Forget about everything except the sheer joy of playing. The monster will melt into that part of you that made you want to study in the first place.
Don't overindulge, but think of the occasional rampage as a fancy dessert . . . it's not on your diet, but life is too short to miss out on a well-deserved treat. Practice Monster will be in a good mood, which means more productive practice down the road. So go ahead and POWER UP!