There are countless methods for creating this kind of selection. You can use the lasso tool, or even the magnetic lasso, to draw a selection around a subject. You can use the magic wand tool to select large areas of plain background. You can use color selection tools or even the quick select tool to make fairly efficient selections that help to separate the subject from the background.
But there’s one selection technique that’s faster than all of them. It’s literally just one click, and it does a tremendous job of isolating the subject from the background and putting the selection just where you want it. It’s the “select subject” button found in the options bar at the top of the screen when the quick select tool is chosen.
The quick selection tool finds the edges of an item within the frame—including the edges of the primary subject, very often—and allows you to paint a selection quickly onto an image. But the “select subject” option takes that control one step farther, by literally requiring just one click of the button to select the subject.
First, choose the quick select tool in the tool panel. If you don’t see it but you see the magic wand instead, click and hold to reveal the quick select tool below it. Then, drag to that tool and release the click. Now you’ve replaced the magic wand with the quick select tool as the visible tool in the panel; should you decide to switch back to the magic wand, just reverse the process.
With the quick select tool active, you’ll see that the options bar at the top of the window now offers options specific to that tool. So, in this case, these are options for using the quick select brush (including brush size, as well as additive or subtractive brush settings), the “sample all layers” and “auto enhance” options, which again are specific to the brush, and then two buttons. It’s here, as they say, where the magic happens. The first button is the most important, as it’s the “select subject” button. When you click it, the application will think for a moment and then, voila, produce the marching ants of a selection that has magically appeared at the outline of your subject. It works tremendously with portrait subjects against plain backgrounds, but it also works darn well when that portrait subject is outdoors with a busier background. As long as there’s some depth of field separation between the two, the “select subject” button tends to work wonders.
Should you need to clean up your selection a little bit—and most of the time, that’s part of the process regardless of how the selection was made—you can click the second button to launch the “select and mask” controls and then use the “refine edge” functionality to really put the finishing touches on the selection.
No matter how you slice it, though, the one-click functionality of the “select subject” button is by far the fastest and easiest way to isolate the subject from the background.