@fivefoldenvy Although unless the reference or my illustration itself is meant to be quite simple, the objective isn't to try and directly replicate all of the reference, unless it's meant to look realistic.
Replicating the general effect is usually enough.
@fivefoldenvy , such as the position of the jaw, etc.
Meanwhile, during the process of drawing, I just eyeball the reference, primarily to either confirm or establish anew the scale and distance of various elements, and make adjustments.
It does take practice.