For more accuracy, put your picture to the mirror. Also take your reference pic and put it there too! You'll see clearly differences between the two. To measure out where the features go, take an envelope, piece of paper or a ruler (straight edge)... anything to vertically represent your line placement and try this: Take your reference pic, put the straight edge against the edge of the smile line and see where it lands near the eye. Then do the same on your drawing, if it doesn't land in the same place, adjust. (TIP: Tilt both pictures have all the vertical lines going at the same direction. How? Tape both pics to drawing board with T-square is easiest way)...or just eyeball it!