The UNDO button.
In almost all editing programs PC users have been able to press "Ctrl+Z" ("Command+Z" on Mac) to undo their last actions. The continued press of this hotkey allows users to continue to undo until they've reached their desired earlier action. A simple but very useful hotkey that used like crazy by artist.

However, Photoshop does not work this way by default. Instead, this commonly used hotkey only takes you back one action. Pressing it again oddly enough will undo your undo. This forcing artist to use a more complicated Undo hotkey to get the desired action.

I figured out the fix years ago but never thought much about sharing it for I assumed others would figure it at as easily as I did. After recently watching a good number of YouTube Speed Art and Photoshop videos online, I've learned one thing. I'm pretty much the only person to have figured out this simple fix. Even the Photoshop art masters seem to have over looked it.

So I bring to you the fix. And at no extra charge, I start the tutorial with how to fix the program's Scratch Disk error. Enjoy and feel free to share.

If the below image doesn't load, then go here:
http://sespider.deviantart.com/art/PhotoshopUndoFix-377583626?ga_submit_new=10%253A1371085025