Enable Multiple Undos in Photoshop CC using a Keyboard Shortcut
Photoshop's default to undo a previous action is command+Z (Ctrl+Z on windows). This takes you back one step. If you press it again however, it will redo what you have just done. Frustrating when you need to step backwards more than once, as most people want to do.
All you need to do is change the keyboard shortcut. The default to step backwards more than once is Option+command+Z (Ctrl+Alt+Z). If you're fine with that than you can stop reading now. If you want to change it to command+Z than follow these steps:
1.Open Photoshop and go to Window->Workspace->Keyboard Shortcuts and Menus...
3. Click and delete the shortcut and in the empty box hit command+Z (Ctrl+Z).
This will trigger a warning message that says the shortcut is already in use. Select Accept and Go to Conflict.
You occasionally want to toggle back and forth to see the most recent change so this does come in handy.
6. Select Accept and OK.