Ur boxes are good. I can clearly see improvement regarding perspective on ur later boxes.

I can see some of lines are wobble at its end its because u tried to stop ur pen before reaching the ending point to avoid overshooting instead try to lift ur pen when ur near the end point, at the end point u should lift ur pen completely from the paper ( like plane take off)

I dont know why didnt u hatch ur boxes. Hatching improves ur line accuracy and confident. Its like practicing lines. And dont redraw ur lines it draws attention to the viewer and also dont correct it.

And here is a tip for drawing inner corner FIGURE. This figure gives relationship between the lines. Its normal to have inaccurate inner corner. It can be improved