Heyy, I'll post my process here when I have free time. And to answer your question. I use a mix both. I prefer using the Loomis Method on the initial stage where we make the circle and determine the angle of the head, and of course plotting of the features like where the nose goes and where the chin is. Then after that I transition to Reilly to determine the planes of the faces. This is useful in shading and painting the face, and helps a lot too to determine the correct proportion of the face and its features.
It'll all make sense once I show my process, but hopefully my explanation alone makes it clear
Goodluckk and have a good day!