Andy Heatwole has written pretty interesting techniques on how you can clone yourself using a sturdy tripod, a camera with a timer function, and static lighting.
“Start the camera’s timer and place yourself in the scene. After the exposure is made, start the timer again and reposition yourself for the next image. Repeat these steps until you have photographed yourself in all the positions and poses you’re needing. Remember to never move the camera or change the focus. Also, make sure you never position yourself in front of or behind an area where you have previously posed. If you do, …”
See also: Photography Tips | Photoshop Tutorials