Quote (INaga @ Apr 10 2013 10:12pm)
https://sphotos-b.xx.fbcdn.net/hphotos-ash3/r90/561433_542378069146178_1097651764_n.jpg
Good, but in general, vanishing points are going to be further away from eachother than that, thats why the box on the left and your first box are so distorted. They move too far up and down in relation to how wide your VPs are.
Now that you understand a little of perspective, you could try doing some observational line drawings of simple objects on your desk, like pens, tissue boxes, stapler, fruit, bowls, etc. Or you could try to nail the perspective. Thus far your stuff is pretty incomplete. You want to do tons of boxes that are perfect, not 2 or 3 mediocre ones. So I your going to need to put much more time into each exercise if you want to gain anything.
This stuff seems boring, but the perspective trains your understanding of space, and still life line drawing trains you to take your time and observe. Heres some examples i got from google images.
lots of boxes
http://www.jennamagee.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=10756&g2_serialNumber=8
observational still life (its pretty bad but you get the idea)
