Every photo manipulation application offers a gradient tool. But Photoshop’s is special. Not only can you paint a soft transition from black to white, you can also soften the transition from one image to another. The gradient tool fades, swipes, and more.
Many folks select images in Photoshop with the likes of the Quick Select and Magic Wand tools. Highly automated, but these tools rarely work accurately. Experts use the Pen tool. Using the Pen tool is an art form worth learning, because it always works.
One of the oldest, most abstruse, downright incomprehensible commands in Photoshop, Calculations lets you merge two channels to create a new alpha channel. Learn it: It’s the backbone of masking.
Many of Photoshop’s best features can only be accessed from the keyboard. Like, how would you know Alt+Backspace (or Option-Delete) fills with black? Watch. It gets better.