Sometimes you’ll want to add a Photoshop adjustment layer to affect only certain parts of your image and not the whole – here’s a quick tip
You can use adjustment layers with a selection, so that they only affect certain subjects and not the entire image.
All that’s required is a selection to start you off, using such tools as the Quick Selection tool or the Magic Wand tool.
Once that’s been pinned down, simply apply the adjustment from the Layer menu>New Adjustment Layer (or from the Layers palette) and see how the selection attaches itself to the mask of the adjustment.
On this image, the Quick Selection tool was used to single-out the sky, and then the Gradient Map adjustment layer was applied with a new colour.