Sami Mohindi

I don't know other people's methods, but I can share mine with you. For grayscale tattoos...once you have the pattern or design how you like it in photoshop or gimp, invert it so that it's white instead of black. Then make it 50-70% on opacity. (50% works well for faded). After you've uploaded the texture, and put it on, add a gray color to it. Darken until you get the right level of "faded-ness" you want. You can also use colors other than grayscale with the semitransparent white tattoo texture! I've done some henna tats with it.