Formal elements are the different aspects and styles in photography, including line, shape pattern, texture, tone, and focus. 

Lines are the clear imaginary lines that lead your eyes. They can be straight or curved.

In the photos below, the straight and diagonal lines of the road and railroad tracks lead your eyes. 

         

Shape is the combination of geometric and organic shapes. 

In the photo below, the shape of the cat shows the organic shape. 

The pattern is the repetition of an object to create rhythm. 

In the photo below, the conical bamboo hat bells hang in the pattern. 

The texture is what the photo would feel if you could touch it; for instance, the surface could be rough, smooth, sharp, etc. 

In the photo below, the ocean waves have a smooth and natural texture as they move. 

The tone is the shades of lightness and darkness. 

The sky has a shade gradient from dark to light in the photo below.

Focus is what leads the viewer to see; this usually creates a contrast to the rest of the photo. 

In the photo below, the plum in the center is the focus because it has the most remarkable contrast. 

All the pictures above are the pictures I took myself 🙂