You've got the right idea when it comes to pose variation, so that's a good start! Your lighting isn't anything particularly special, but in photos 3-5, it works to show off the true colors and highlight your face. That's good for now.
There's a lot of clutter in your backgrounds-- clear that up, or zoom in to hide it! You also want to avoid objects that go "through" your head. That poster (periodic table?) is a massive distraction from your lovely wig and makeup.
Composition is important. All of these shots feel very similar. They're taken straight on, with you in the center doing your pose, from the same level. Move your camera around to change the perspective. Prop it up on a pile of books, tilt the front up with a slanted binder, shoot from the side instead of directly on. Variance like that will give you a much wider variety of results with minimal effort from you.
I'd recommend reading up a little on composition, and this is a decent place to start: http://www.exposureguide.com/top-10-...ition-tips.htm
There are tons of articles out there online if you just search around!