Imagine a small square on the ground and you are standing in the middle of it. Jump out of the box and back to the start position working your way all around the box. Then repeat with your left and right feet.
So it looks like this:
Foreword-Back
Right-Back
Back- Foreword
Left-Foreword
Repeat the pattern again with your left and right feet separately.
Then repeat in the opposite direction
Jumping the pattern with both feet and each foot individually = 1 rep