Time to bring back the coffee. From the Layers panel click eye icon in front of the coffee group to reveal it.

I want you to download coffee stain brush set from this page. Change foreground color to #6D5631 and paint one or two stains under the cup. Make sure you use brush size smaller size smaller than the cup or it will looks weird.



You can stop here but I want to add more realism to this image. Create new layer and draw one more stain out side the paper napkin. I want to make impression as if the owner forget to put the cup on the napkin.

Coffee stain outside the paper has to be different from those inside. Ctrl+click paper to create selection based on the paper size.

Make sure the coffee stain layer is still active. Open Levels (ctrl+L) and move black slider to 50 to make the selected stain lighter.

We're done with this picture. Finally, you might want to add texture for the background. I hope you learn one or two techniques from this tutorial and have good time while doing it. Click on the image below or click here to see it in full size.
Photorealistic Coffee Cup.psd | 7 MB