Beginner Photoshop Tricks

Selecting Colors from an Image Quickly
To turn any color into the foreground color Press I to activate the Eyedropper Tool and then click on any color in your image. To turn that color into the background color, press the ALT Key and click on any color in your image.

Change Brush Tip Sizes Quickly
With any brush selected you can press the Right Bracket Key "]" to increase the size of the brush tip, or Press the Left Bracket Key "[" to decrease the size of the brush tip.

The Move Tool & the Arrow Keys
You will want to get in the habit of activating the Move Tool with the keyboard shortcut, “V”. Once the Move Tool is active you can use the arrow keys on your keyboard to nudge a layer or selection in 1 pixel increments. If you want to speed things up, press Shift along with an arrow key to nudge in 10 pixel increments.

Hide Your Palettes
To hid all your palettes press the tab key once. You can press the Tab key again to bring them back. To hide all your palettes except the toolbar press Shift+Tab.

Zooming In & Zooming Out
To use the zoom tool press CTRL and the plus sign "+" (Mac: Command and the “+” sign). To zoom out press CTRL and the minus sign "-" (Mac: Command and the “-“sign).

Take a look at this video from You Tube about the Eyedropper Tool