LET’S LEARN THE EDGE REFINEMENT TOOL!
First, get a picture and import it into Photoshop (for demonstration purpose, the hairier the better). For example, we have this hairy dog.

Next, make some effort with the magnetic lasso tool to wrap around the basic body structure of doggy here. Right after, click the “Refine Edge…” button on the top tool bar.
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Oooooo, now we have this interesting new window opening up along with the lassoed body. Let’s see what it has to offer, shall we?

First up, the Edge Detection Tool. It allows you to reveal more of the original edges as you go further down the size of the radius toolbar. Don’t put too much, else everything becomes too blurred and less pixelated. The Smart Radius checkbox fixes this alignment as you control the radius, but gives you less leeway on the amount of defining of edge.

For a more personal highlighting of edges, there’s the Refine Radius Tool brush. Acting like a brush, you go over the areas you want to have more defined edges, and it will appear like so. PRESTO! The Erase Refinement Tool has the same function BUT the opposite result AKA erases edges.

The Adjust Edge section has many functions that act to customize your edges, such as:
Smooth: Gives a clearer and less sharper edge

Feather: Gives a glowy and faded feel to the edge

Contrast: Gives a sharper look to the edge

Shift Edge: Moves the modified edge boundary inward towards the center or outward

And there you have it! The basic tool to help you highlight those pesky hair details without spending hours lassoing every single stand. Hope you enjoyed this tutorial. Now go PHOTOSHOP!