A big part of being a professional photographer is making sure your workflow is as efficient as possible. Even if you’re not a professional, using keyboard shortcuts in Photoshop will drastically shorten the amount of time it takes to edit photos. You can use this time saved to be more creative with your editing, or even join a water polo class.
All of these shortcuts work for PC computers as well! Just use CTRL instead of Command and ALT instead of Option.
List of Keyboard Shortcuts
Workflow
Save As: Cmd Shift S
Save for Web: Cmd Shift Alt S
Undo: Cmd Z
Step back: Cmd Alt Z (lets you keep going back in time)
Stamp Visible: Cmd Shift Alt E
Hide selection: Cmd H
Fullscreen: F
General
Default Colors: D (Black and White)
Flip Foreground and Background Colors: X
Rotate View: R (Make sure OpenGL setting is turned on in your preferences)
Move around image: (Hand Tool) Hold Spacebar
Layers
Invert: Cmd I
Delete Layer: Delete
Transform: Cmd T
New Layer: Cmd Shift Alt N
Duplicate Layer, or if selection is active, Duplicate Selection: Cmd J
Transform menu: right click on layer, Cmd T
Step and Repeat: Cmd Alt T(first step), Cmd Alt Shift T (second step)