TIP: Layer Mask Quick Tips

I've found myself using these Layer Mask shortcuts more and more lately, so I thought I'd pass 'em on just in case you might find them useful: (1) If you want to see just the Layer Mask itself, hold the Option key (PC: Alt-key) and click on the Layer Mask thumbnail itself (as shown here--click for a larger image). I use this one to quickly see if I've missed any areas when painting in an area of my mask. (2) Since I sometimes accidentally find myself painting on the image instead of the mask, I use Command-\ (PC: Ctrl-\) to toggle between the image being active, and the mask. (By the way, that's the Backslash key). Lastly, there's Command-I (PC: Ctrl-I) which inverts the mask from white to black (the same as holding the Option/Alt key when you first create the mask). That's it--three from me.