Holy smokes, those Sargent studies look great!! I love it when things start to click! I'm definitely seeing improvement across these exercises. The more cubes you draw, the more you'll get the hang of it! Once you give your brain some time too cool off, a really good next step here is to go back and analyze your earlier cubes and try to adjust and true them up. Try to find the correct center line in your boxes, and evenly place the thirds of the brow line and nose line, and extend your lines out to the vanishing points. By extending your lines out to their common vanishing points you can see more clearly where your lines start to deviate. The convergence should be fairly subtle unless you're dealing with exaggeration from an extremely close lens, or view point. Take a look at your earlier boxes and either draw over them with a colored pencil, or some tracing paper to see where your proportions and alignment have come off. You can use a ruler to track these lines off more accurately and check your work. If you're having trouble finding the center of the box, remember if you draw an X from corner to corner of the box you'll find the exact center, even if that plane is tipped into perspective. The center line should follow the convergence of your other lines in that line system. Cubes and Perspective takes a lot practice before you start seeing this subtlety, so look at this phase as adjusting, not fixing. Our first lines are not wrong, they're always just a best guess, so we can always go back and adjust to make things closer to what we want. Here are some free lessons from the Perspective Course on how to wrangle these cubes! Hope this helps! https://www.proko.com/course-lesson/assignment-control-depth-on-paper-with-a-simple-box https://www.proko.com/course-lesson/assignment-perfect-cubes-from-your-minds-eye https://www.proko.com/course-lesson/assignment-tumble-cubes https://www.proko.com/course-lesson/measure-depth-keep-track-of-imaginary-space

Some great observations from @Paul M here. Perspective is tough, so give yourself some grace with this skill, it takes some time to absorb and execute all of the information. You don't always need to draw vanishing points on your page, but when you're getting started it helps to trace off your lines to see how they converge in the distance and make sure you're hitting a common vanishing point. If I'm drawing without actually placing these vanishing points I like to put something in my periphery or mark somewhere on my drawing board to give myself a target to aim my converging lines toward. I did a draw over of your cube to show where you're on point, and where you're getting a little skewed. Your closest vertical line, the line hitting the corner of the brow, is spot on! You can feel that bump on corner of your own brow where the side of your head meets the front of the face. This is a great landmark to look for to place this vertical line for the cube. In two-point perspective, you have two vanishing points for your horizontal lines. Your horizontal lines going left will converge to a common vanishing point (LVP), your horizontal lines going right will converge to a common vanishing point (RVP), and your vertical lines will all remain parallel with no convergence. From the vertical line you established on the corner of the brow, try to find the "Y" of the next two closest lines on the top plane of the box. These guide lines will help you place the rest using the features as landmarks. It helps to look for the angles of the hair line, brow, nose, and chin, and trace them off towards their respective vanishing points. These lines will all converge to a common vanishing point, but the convergence is subtle. The distortion of your cube is caused by your vanishing points being close together, so the convergence is exaggerated. The further apart you place the vanishing points, the less exaggerated the convergence. It helps to draw through your box to reveal the hidden side like you have x-ray vision. When you can see how your lines converge on the hidden side it can show you where you're off! Keep practicing, and take a look at the demos/critiques for this lesson, Stan will give a lot of tips for these common struggles in those lessons! Also, check out the Zolly app if you're looking for some perspective practice, there are a bunch of free basic shapes to get you started. Hope this helps! https://www.proko.com/zolly-app