As in breaks from your work!
We've all been in a groove, plugging away at our code and then hit a wall. If you've been at that wall for a while, take a break! And I don't mean sit at your computer and do something else; get up and move! Stretch, take a walk, go get some water, or something else to get away from the workspace.
This has always helped me get out of the rabbit hole that is debugging. Thinking about the problem while away from the keyboard lets you come up with a new plan without immediately putting it into code, and running through the logic in your head without the code can reveal the key to moving forward.