1. In face anatomy drawing, the width of a face is generally five eyes

2. In real life, when viewing from the side, eye whites are visible, but the iris of an eye isn’t.

3. The upper lip is nearly always thinner than the lower.

4. The outer corner of the eye can be higher than the inner, but not the reverse.

5. Facial details should decrease the larger the scale of a drawing

Masculine vs Feminine Differences: The Differences Between Male and Female Portraits | Envato Tuts+ (tutsplus.com)

1. Men have longer and larger faces than women.

2. Men tend to have thicker eyebrows.

3. Definition of the upper lips will give the mouth a more feminine feeling.

4. Male faces have stronger jawlines and a more square-like chin.

5. Female portraits have longer and thinner looking necks.

Advanced Facial Studies: Human Anatomy Fundamentals: Advanced Facial Features (tutsplus.com)

1. A male’s neck has an Adam's apple and a female neck doesn’t.

2. Before adolescence, there is no difference between male and female faces.

3. Babies and toddlers have no eyebrow ridge and no visible cheekbones.

4. The best-known identifier of an Asian eye is the epicanthic fold

5. In late adulthood male hairlines may start receding.

6. In portraits of people in older ages, skin hangs at the jaws

Aging: Human Anatomy Fundamentals: Drawing Different Ages (tutsplus.com) 

1. The body length of a newborn is 2.5 heads.

2. The eyes of newborns only take their final hue between 6 months and 1 year.

3. At age 4, a child’s height is at least double its birth length.

4. A toddler’s body begins to slim down a bit, losing the rounded tummy.

5. At middle age, elbows and kneecaps show wrinkles.

Guilty Expression: Downwards gaze, avoidant eyes, minimal expression. Shrunken features.