February 6, 2013
Double clicking the Quick Mask icon in the Tool panel in Photoshop enables changing the color of the Quick Mask overlay. This can be helpful when viewing the Quick mask over an image where the subject or background is similar to the default red overlay. Note: changing the Quick Mask color will also change the Overlay option (in View Mode) when in Refine Edge.

December 16, 2010
While in Quick Mask mode, tap the Tilde key (~) to display Quick mask as a grayscale mask. Tap it again to return to the red rubilith overlay view.
July 30, 2010
• “Q” will toggle between Quick Mask and Normal Mode.
• Double click the Quick Mask icon on the tool panel to view Quick Mask Options.
• Command (Mac) / Control (Win) + 2 to view the Quick Mask, yet edit the composite image. Note: You can view the Channels panel to see what’s happening under the hood – notice how Command (Mac) / Control (Win) + 2 targets the RGB image instead of Quick Mask and that Command (Mac) / Control (Win) + 6 will target the Quick Mask).
October 30, 2009
Option (Mac)/ Alt (Win) -click on the Quick Mask icon to invert the selection when entering Quick Mask mode.
October 29, 2009
Double click on the quick mask icon to access the Quick Mask Options dialog box to change color, transparency and opacity options.