BALL.

I Set up a file as below in Photoshop. The size was 788 pixels by 576 pixels. I worked on a transparent layer.

I drew a small round ball. I use the brush tool and draw out an ellipse using the elliptical marquee tool, I was holding down the option button to create a circular selection Then filled it with the colour. 

I duplicate the layer on the Layers Panel. by Pressing Command + J on the keyboard.

The duplicated object will be directly over the original. So I moved it slightly with the move tool.

I was using the Transform Tool, I squash the shape slightly. to look like something like the one below.

I then duplicated the squashed layer and then edited the shape a little more. This will be used when the ball hits the ground.

I opened the Timeline and selected Create Frame Animation

I turned off the two layers containing the squashed balls.

I moved the ball to the top of the page.

I add a New Frame by pressing the create new frame icon on the Timeline. It is the icon next to the dustbin.