To create a cube, position the cursor at a corner and drag as though you are creating an isometric rectangle in front view. Once the rectangle is created, release the mouse and immediately drag away from the cube without clicking to create the cube depth. The cursor will follow the isometric angle that connects to the central point shared by all faces of the cube. When the desired depth is reached, click the mouse to finish the cube. You can hold down the command/control key to start with the side face or alt/option key to start with the top face of the cube.