Remove subjects and background elements quickly with the Magic Eraser tool in Photoshop
The Magic Eraser tool is ideal for removing such things as blue sky from between trees with a single click.
It works just like the Magic Wand tool, but instead of forming a selection the pixels are deleted.
Set Tolerance to 40, untick Contiguous in the Options bar and click once on a colour to remove it!
Turn Caps Lock on to change the cursor into a set of crosshairs rather than the Magic Eraser icon.