Stage: 3 and 4 Challenge Level:
You may find it helps to do your drawing on plain paper, with squared paper beneath it to make it easier to draw a horizontal line and vertical lines.
All vertical lines remain vertical, other lines are oblique - you are trying to construct what you actually see in the photo.
Start by drawing a horizontal line and putting the two vanishing points on it, one near each end of the line.
Draw a vertical line representing the central vertical edge of the front green cube.
Draw construction lines from both vanishing points to both ends of this vertical line.
Considering the relative apparent proportions of the vertical edge and the bottom left and right hand edges of the green cube, and draw in the left and right hand vertical edges of the front green cube, and then the extreme right and left hand edges of the rear green and blue cubes.
Continue adding construction lines from both vanishing points to all cube vertices, using intersections of the construction lines to locate further vertices.
When you have constructed the bottom layer of cubes, think about where you want the right hand edge of the yellow cube to appear to meet the vertical/right hand edge of the red cube, and what the apparent height of the red cube should be relative to the green cubes.