An oldie, but let me do some brainstorming.

1. If you are going to have thousands of clips, you definitely need to construct a rig, not only for the models but also for the lights and cameras.

For the model make one structure to be adapted on a comfortable chair that gently directs the orientation of the head.

2. Prepare a digital projector to shot a grid or a silhouette from one side of the model (be careful with the eyes) as a reference image.

3. Or prepare a set of orthogonal cameras, that can Livestream to a computer. If you are using windows, there is a small program called "Ghost win Real transparent windows" that can overlay one application over the other, a reference image. These cameras need to be also attached to the rig.

4. You could use a flat background, so you can align the clips in post pro.

5. Combine all the above.

An oldie, but let me do some brainstorming.

1. If you are going to have thousands of clips, you definitely need to construct a rig, not only for the models but also for the lights and cameras.

   For the model make one structure to be adapted on a comfortable chair that gently directs the orientation of the head.

2. Prepare a digital projector to shot a grid or a silhouette from one side of the model (be careful with the eyes) as a reference image.

3. Or prepare a set of orthogonal cameras, that can Livestream to a computer. If you are using windows, there is a small program called "Ghost win Real transparent windows" that can overlay one application over the other, a reference image. These cameras need to be also attached to the rig.

4. You could use a flat background, so you can align the clips in post pro.

5. Combine all the above.