>>9108345There's an easy way just using FaceApp and there's a way that involves getting a good pic, and erasing all the background, filling it with a skin color and darkening highlights and stuff. There's a tutorial for both ways on Youtube. The second is much more useful for real life people. The FaceApp method is really good for just getting a caw without a default face
With a face texture the first thing you do is line up the eyes, nose and mouth and pretty much attaching/anchoring points of the face texture to the model so don't be afraid to make some things like the eyes too big at first to match it to the face texture you're using. After you put on the face texture you can go back and actually adjust eyes and nose and stuff