I have a Bohin eversharp pencil with a fine lead to use, love it. The leads come in several colors, including white. Not available everywhere but ask for it in the quilt shops. There is also another Bohin transfer set that is used for quilting but the leads are very large, they work great for longarm guidance.
I do alot of transferring for embroidery and quilting and have found some pencils in the art dept. One is General's Scribe All, comes in black and white; another is Dixon Photomark. The General's pencils are water soluble and do go away with washing, although embroidery usually covers the lines.
A good and large light box is still a good investment, beats standing next to a window and copying designs.
Carol J.