Step 1: Start the adjustment
With an image open, select the Adjustment Brush icon from the top Options bar. This brings up all of the sliders of things you can selectively adjust. We are going to start by tweaking the highlights of the sea, so we push the Highlights slider to the right and then click with our brush to make a pin in the sea, before beginning to brush over the area we want to affect. You can change brush sizes using the [ and ] key shortcuts.
Step 2: Multiple adjustments
When you have treated the sea, you can choose to add a new Adjustment brush to the image by selecting the New Radio button on the right, above the sliders. We now increase the clarity a touch and brush over the grass, before adding yet another brush. Increase the clarity and saturation to brush over the sky area. When you brush you are creating masks, meaning that you can go back to any of the brushes you have created to tweak.
Step 3: Masks and pins
When you apply a brush, the pin is left behind. Hover over any pin and you can see a mask (this will be a white by default, but you can change it) of the area being affected. You can then easily make further changes to the masked areas by clicking on the pin to reactivate that brush and use the sliders. Make sure that the Add Radio button is selected to continue adding to the brush’s mask. Repeat any of the steps as needed to finish.