I'm going to use boxes numbered 1,2 and 3 as separate examples. For number 1 below the horizon line, you did a good thing giving the box a slight tilt, your vertical lines however will not tilt. For number two above the horizon line, it's ok to drop that plane a bit and show a bit more of the underside of that box. Lastly, for number 3 I don't think that the top plane will be as open. With a 2 point perspective, the horizontal lines of the boxes you draw are not as extreme on a full grid. I'm honestly going to suggest that you don't draw your own grids at first and stick to one full sheet of paper to practice on. That way you'll have one clean practice session to make sure the boxes you make are consistent with each other. Use a ruler still if you need to just get a sense of how lines contrast for cubes based on where they are on a larger grid. | Artwod Feedback