Page 1 - Gathering all the parts

The basics behind a clone shot a fairly simple:
1. You need to shoot the backdrop for the scene totally empty. You will need this to show through all the layers no matter how they are masked.
1a. If your camera supports the ability to lock in the color, you should do it now so that the ambient color of the lighting of the scene remains as consistent as possible throughout all the shots, regardless of where your actor is.
2. Then you need to shoot your actor in all the various places around the scene that he/she needs to be. Be very careful to be sure the camera doesn't move at all!
3. Once you have all your video clips, you're ready to start.
4. You place all the instances of yourself on the timeline and mask out the parts that are obscuring the layers underneath.

What I'm covering here will explain how to do a clone shot with the camera sitting perfectly still and nothing else going on in the background. With some planning, these same techniques can be applied in other circumstances where the camera moves. But, I'm not going to get into that here.

Here are the still frames of each of the 5 clips I need for this scene (scaled down a bit for easy viewing).

Now the first thing you'll notice here is that the lighting is inconsistent. I couldn't find a setting on my camera that let's me set the color like I suggested earlier. Bummer.

Anyway...

The next step is to set everything up in After Effects. The backdrop image doesn't need to be a video clip. In this case, I sent out the first frame of the video as a BMP and used that for the backdrop. You can do it that way, or make sure that you film enough time of the blank room to fill all the time you'll need. Either way, you start by putting the backdrop on the timeline of the main composition.

Go on to page 2: Setting up the timeline with the Doorway footage