i honestly think that the cross lines are useless i plan the face with a circle base and a crossed line but when i draw the head, the cross lines didn't look great to draw the face like when i drew the head and when u look at the crossed lines when u draw the eyes, the eyes are a lil too low or the mouth just.. it'll look weird if u follow the cross base if it isn't at the right place if that makes sense

Oof I use both lines