Image caption, Draw half a circle that starts and ... hand to move the paper around will make it easier to cut along the line. Place your paper down and decide which way you are going to fold ...

Hold your paper with the edge you want to cut at the bottom If you want to draw cut lines with a pencil and ruler, do that now. Otherwise just keep an idea of the lines in your mind. Why not try ...

Of course, the part of the video that shows the pencil moving underneath the cube is down to clever editing (no-one's drawing ...