Breast position.
How to correctly position breasts on the chest when drawing.

Drawing realistic looking breasts.

How to draw Breasts

As the body changes position then so do the breasts. They are positioned over the pectoral muscle and so with every movement of the arms and upper body the breasts positions slightly change on the body. Below is a selection of sketches showing the position of the breasts in relation to the body. Breasts-nude side profile Breasts-nude side profile leaning back

 

In the sketch of the model bending back, you can see that as the body bends backwards the breast position changes as it is drawn up by the muscles of the chest and shoulders. Note also that the stomach flattens and the rib cage becomes more prominent.

In these sketches, the breasts are sitting naturally on the chest. Note how the movement of the arms affect the position of both breasts and how by raising an arm the breast lifts higher on the chest drawing the nipple up and out. Breasts frontal nude with arm raised Breasts side profile with shoulders back Breasts-frontal nude leaning back with arm raised Breasts-Seated nude leaning back

In the sketch of a seated nude, you can see that by leaning back slightly on one arm the breast rolls back and slightly flattens into the body with the nipple pointing out slightly.
In the example of a nude lying on her side, you can see that her breasts hang from her body and the nipple points slightly to the floor as gravity draws the heaviness of the breast down causing the tissue and tendons in her chest to stretch as they support the breast.
All of the examples above are intended as guides for you to use and reference for your own life drawing projects.  Breast position. Nude laying on her side