A lot of tutorials meant to teach you how to Photoshop a tattoo onto a photo only show you about half of the process. Sure, they show you how to paste an image and get it in the right spot and decrease the opacity so it looks a little faded, but they still end up looking stuck on. This thorough tutorial shows you how to get the tattoo to look like it wraps around the body by using a displacement map as well as how to get it tinted to a natural color. The result is pretty convincing and even looks as though the tattoo has had some time to age.
How To Photoshop Realistic Looking Tattoos