Photoshop - Essential Hotkeys

Shortcuts

G - Gradient/Paint Bucket
S - Smooth
I switch smooth to S. sculptors need it ZBrush so, why not painters/illustrators?
H - Sharpen
O - Dodge/Burn
I - Eyedropper
B - Brush
P - Pen
V - Move
E - Eraser
Q - Quick Selection
L - Lasso
Not in default settings but man, is this a powerful one.
W - Wand
Let’s look at the wand tool as an opportunity for something rather than a random quick selection. Random can also be unexpected. This actually is a handy tool for photomanipulations as it will intuitively separate contrasted darks from the lights in your chosen photograph
M - Lasso (Modified from Eliptical Tool)
U - Rectangle Tool
I want to have the magic lasso by my side  at all times, especially for things like landscape designs or general photomanipulations. this is a great one for building terrains or if you generally are looking for a reliable contrast-edge delivery to the canvas.
[ or ] - scroll through layers
Shift+[ ] - Change Brush Hardness

Modified Shortcuts

• CTRL+B - Brush menu (modified from color balance)
• CTRL+E - Stroke Path
• CTRL+W - Make Selection (Pen)
• CTRL+D - Clip MASK
• CTRL+C - Layer Menu
• (changed from CTRL+Shift+N)
• CTRL+X - Color
• M - Lasso (Modified from Eliptical Tool)

i.e. these shortcuts are modified for reasons to create a better professional experience when working on projects.