6:45 PM, Friday May 29th 2020
I would say to extend your lines more when checking your convergences. It's also important that you reinforce the solidity of your forms with subtle line weight around the silhouettes, and to fill the front facing plane with hatching lines to better describe its orientation in space.
I feel like you may have rushed a bit when doing this exercise, so I suggest you complete 30 more boxes, making sure that there's some subtle thickness around their silhouettes and that you extend your lines more when checking convergence.
2:56 PM, Tuesday June 9th 2020
Will do so. Thanks for your critique :)!