Krita

Krita is a lightweight photoshop clone for linux. It is amazing. The only downside to Krita is that the actions/macros are very limited. I do not like gimp as much, but since it is the popular choice there will likely be more plugins/support so it is a safe bet to have it installed and pre-configured the way I like it just to be safe.

Configuration

Photoshop-Inspired Hotkeys

Settings > Configure Krita:
    - Keyboard and Shortcuts:
        - ShortCut Schemes (bottom): photoshop_compatible

Misc

## Display:
Top Right     > Colour Wheel, Brushes, Tool Options
Bottom Right  > Layers, Alpha



Settings > Configure Krita > Display
  Enable OpenGL
  Enable OpenGL Shaders

Hotkeys

Hotkey Overrides
Add New Paint Layer	F2
Deselect	CTRL + D
Fill with Foreground Colour	Alt + Backspace
Fill with Background Colour	Ctrl + Backspace
Select an Area by it's outline	Shift + L
Select a Polygonal Region	L
Select a Colour from the image or Current Layer	I
Transform a Layer or Selection	V
Select a Contiguous Area of Colour	W
HSV adjustment	Ctrl + U
Levels	Ctrl + L

Pre-Existing Hotkeys
Alt + Shift + Space + Drag	Rotate Canvas
Tab	Hide Layers
Shft + I	Colour Picker
Shft + Drag	Resize Brush
e	Toggle Brush/Eraser

Special Notes

Layer Mask uses eraser + Brush instead of white/black.

Paths can be saved! You just need to create a vector layer. Make sure to mark them as hidden though so that they do not turn up on the final image.

PSDs can be opened, and saved. To save as a PSD file, save as photoshop image in Export.

Old Photoshop brushes (.abr) import support is being worked on. Theoretically (had not worked for me), they can be loaded into Krita by placing the .abr file in:

~/.kde4/share/config/krita/brushes