Step 1: Gimp
Step 2: Get the photo
My first time making the lightsaber effect I used the pic above. I wanted to use it again for this instructable but I could not find the pic online so I will use my own pic of me holding a lightsaber.
First choose the pic you want to use. Start up Gimp and open the pic within Gimp.
Step 3: Reference point
If your picture has a stick where the blade should be, you can skip this step. But if your pic is like mine and has just the hilt and nothing to tell you where the blade should go, you need to create a reference point so the blade does not look crooked. Take the (insert) tool and make a strait line from the bottom of the handle to the top of where you want the light saber to be. Make sure the line runs straight down the middle of the handle. Next make a white spot by the top of the line. This is going to be the reference point.