How often should I take a photograph to track my progress?

It is your choice. However, we recommend taking the photo once per week. It’s essential to try to use the same mirror/background/lighting for each photo as this can affect the image, and you may not accurately see your progress.
We suggest you take a photo yourself using a full-body mirror, preferably in similar clothing and with similar lighting. Or you can have someone else take the picture for you. Again, try to use the exact location, background, and lighting for the photo.