When coloring pictures with complex backgrounds, it is best to simplify the complexities. Blur the particularly messy parts, or replace them with other clean background materials. This way the overall feeling will be much better.
Original picture
final effect
1. Open the original image material, press Ctrl + J to copy the background layer, select the pen tool, outline the sky part, and convert it to a selection, as shown in Figure 1.
<Figure 1>
2. Execute: Filter > Blur > Gaussian Blur, the value is 15, there is no need to cancel the selection after confirmation.
<Figure 2>
3. Keep the selection and press Ctrl + B to adjust the color balance. The parameter settings are as shown in Figure 3, and the effect is as shown in Figure 4.
<Figure 3>
<Figure 4>
4. Create an optional color adjustment layer. The parameter settings are as shown in Figures 5 and 6, and the effect is as shown in Figure 7.
<Figure 5>
<Figure 6>
<Figure 7>
5. Create a new layer, press Ctrl + Alt + Shift + E to stamp the layer, click on the channel panel, copy the green channel, use a black brush to paint out the parts other than the skin, and then use curves to adjust the contrast appropriately. The effect is as follows picture. Then go back to the layers panel.
<Figure 8>
6. Press Ctrl + Alt + ~ to call up the selection and create a curve adjustment layer. The parameter settings are as shown in Figure 9, and the effect is as shown in Figure 10.
<Figure 9>