Here ya go. The "ghost" on the left is a Photoshop layer set to 50% opacity. The one on the right is a separate layer set to 100% opacity but with a black-to-white gradient applied from bottom to top. I then painted over the mask where her face is with the paint brush. Don't know why I did that. Oh, now I remember...it was to show you have a lot more control over transparancy when you use a layer mask.