First of all, of course, you should open the material picture above, and then select the pen tool on the toolbar to hook the characters' lips. Then in the upper right corner of the path panel, click the triangle arrow, select the storage path in the menu, and save the current path as path 1 for future use.

Then create a new layer, fill it with gray, and then perform filter-noise-add noise, the number is about 4%, and other settings are the default!

Press CTRL+L to open the color scale, so that the white size and density in the layer can achieve satisfactory results. At this time, the white point may have a little color difference, but we don't have to worry about this, and then press CTRL+SHIFT+U to decolorize the layer.

Then, set the blending mode of this layer as linear gradient, go to the path panel and select the path 1, press CTRL+ENTER to convert the path into a selection, and press CTRL+ALT+D to feather into two pixels; Then add a mask to the layer, and use a brush to treat the dark part of the character's mouth in the mask.

Then use the mouse to select the background layer, click the "New Fill or Adjust Layer" button at the bottom of the layer panel, and select Create Curve Adjustment Layer to adjust the curve appropriately; Then, as in the previous step, the path is converted into a selection, feathered and smeared in the mask.

Copy the background layer, pull the background copy layer to the top of all layers, and then perform the gradient mapping operation.

Then set the blending mode of the copied layer to color filter, and then perform the same steps as the first two layers, that is, transform selection, feather, add mask, etc.