Your portrait of that dude feels really expressive and your pencil technique really complements the atmosphere and I'd say that drawing is pretty admirable. Though, I'd like to point out that the left eyeglass that's in the back is taller than the one in the front, so it kind of throws off space for me in that moment.
For the deerdude, you got me in a lighter feeling atmosphere, so it seems like I would agree that you'd have some good ideas about composition. I only want to say that the head seems to be viewed at a different perspective starting from the shoulders going up, and below that your body has a different perspective so it doesn't attach properly and makes it feel like it's unbalanced. Try working with 1 or 2 vanishing points, it really helps put things together.
I'm not exactly sure what hetalia is, but the drawing looks like it's got nice qualities from the bold pencil strokes. Looks as if there's a nice subtle detail on his cheek, a tattoo. The only weird thing I see is that I can't find where his left elbow is, when you have a simple drawing, attention to shape is pretty critical.
Your last piece has nice textural qualities to it. There's not much I can say since I don't look through surreal art too often, but you can definitely use some ideas from here for more stuff.I'd not the textures, qualities the give it depth/take it away, and the contrast that defines your subject.
Chick with suspenders, not trying to be mean but I saw a guy at first. It was mostly due to the fact that the black fuzzy brush on the arms looked like hair to me. Some of my first thoughts is also that it looks like a nice graphic, but I also saw the thing with the shoulder from the deerguy. The size of the two hands are vastly different, the right shoulder is raised very high, so the right upper arm is a lot longer than the left. To me it's a matter of something in the back is smaller than something in the front.