You may know that a simple keystroke can switch you from one brush to another, but did you know that your brushes are spring loaded? Let’s say you’re painting but want to switch to the eraser tool for a second; just hold down the shortcut key for the eraser (“E”), do your erasing, and when you release the shortcut key, your paintbrush returns!
I’ve found this really handy with masking (or otherwise switching between two colors). I’m masking with white but accidentally paint in the wrong place. I just hold down “X” to temporarily swap my swatch to black, fix the spot, and when I release the “X,” I’m back to white. Sure, I could just hit X, paint with black, and then hit X again to get back to white, but every keystroke is time lost in my book!