I think it's cool that you are practicing your shots, and trying to strengthen your "eye".
Take the can for instance. Go back to the can, and really work with it. Shoot high, shoot low, shoot from the side. Really walk around that can. Take the can to different locations, and repeat the above. Put the can in different situations, and different light, and repeat the above. (Actually this might make for a really cool series, but I digress!)
It's not so much what you will be learning about the can. It's what you will learn about angles, and light, backgrounds, bokeh, and sharpness.
Have fun with your project, because it IS a fun project!