The original cherry on the left was chosen from the group of three. As a start, the Free Transform tool was used to stretch the cherry into a more oblong/squarish shape.To complete the basic foundation for the cubed look, I cut and pasted some areas from the original that contained details I intended to incorporate into the final and to add to the cubed effect. I elongated some of them with free transform. Some of the interior edges on the additions were softened a bit, with the eraser tool at 20%, to make the transition somewhat smoother.I sketched a guide on a separate layer showing the eventual shape/perspective to help in creating a proper cubed look.