Reducing Oily Skin
Open a photo of a person who has oily skin. I am using the photo below I got from a photo restoration site:
Click on the new layer icon at the top of the layers palette to create a blank layer above the background layer.
Select the clone stamp tool and set the options bar with the following setting:
Soft Brush Selected
Sample All Layers: checked
Zoom in on picture by selecting the zoom tool from the toolbar and then clicking on the photo. Find an area that is not oily. With the new blank layer selected, press and hold down the Alt key and click in a non-shiny are to sample the skin color.
Start painting on the problem areas to remove the shine. If you get some unwanted results simply click Ctrl + Z to Undo and then try it again with smaller brush strokes. Continue until you have removed all the oily areas. Here is my finished photo: