It has become a habit of mine to draw the face with as much detail as I can at this stage, but that is my quirk and is not a rule.

PROPORTION

The head height will be your basis for the 8-head rule. I've broken down the measurement on the right image

• From the chin, it is one head down to the middle of the chest. For women, usually this line can indicate somewhere in the middle of the breasts, around the nipple area. From chin to shoulders, the measurement is usually 1/4 of the head height.
• One head down form the chest, is he navel or belly button area.
• From the belly button, go one head down and you'll be hitting the bottom of the "private area".
• One head down, is half the thigh area.
• Another head down and you'll be just below the knee.
• Another head down is more or less half the foreleg.
• And last head down, you'll be hitting the spot just below the ankles.

If you observed, the feet was not part of the measurement. This is because a woman's feet can actually vary in height in relation to what type of shoes she's wearing.

Also, I've noticed some artists having different variables of height when it comes to the forelegs, where sometimes they are slightly shorter or longer. It is basically a form of anatomical preference.