Composition is the art of placing elements to create a compelling and impactful image. There are various concepts of composition that will allow for a stronger presentation. One of these is line. Line is a huge factor in composition. There are various shapes of line that create a stronger image. These lines are known as the S-Curve and C-Curve. In the outlined image below you can see the representation of the S-Curve. You can also make out the C-Curve lines as well. These curve lines are especially important with the female body. When posing the female with these lines in mind, you create a more interesting image that enhances the figure of the female body lines.
The next compositional element is shape. It is easy to create shapes out of the body lines. The body when posed can create very geometric shapes that enhance the image. These shapes are generally more useful when posing couples or groups. In the image below you can see the triangles made in various crops of the image from tight to wide. Triangles are very impactful shapes to use when posing. When posing couples think of a wide base with a narrow top portion. This creates a triangle of two people. When posing families or groups, vary the heights of the heads of yours subjects. When you do this, have some sitting, standing, Kneeling, etc. With this in mind you will vary the heights of each head in the frame and create shape from them.
The Point of Intersection is the concept that the body line is posed in a way (with two people) that each line intersects at a point above the subjects. In the image below you can see that the heads where tilted in to create a triangle and a line that intersects at a point above them. If you think of the body as a line and the head as a hinged point, you will tilt the head in. As long as each head is tilted in you will create a point of intersection. For an even stronger image create a wider and stronger base. With the wider base of your subjects and the head tilted in, you will create an even stronger image!