I would advice you to mentally separate the form of the head from the features, and try to capture the form first, and then find the locations of the features within, instead of drawing the features first and then hoping that they align correctly.
Were I to guess, I'd say the portrait in the lower right hand corner was the final one of this set. It clearly shows a progression of improvement, especially in the shape of the mouth. Good job.
Aunt Herbert
I would advice you to mentally separate the form of the head from the features, and try to capture the form first, and then find the locations of the features within, instead of drawing the features first and then hoping that they align correctly.