File: 1342346438091.png (104.23 KB, 652x772, example.png)
Well, speaking from someone who's been through the phases, I can see a pattern of something I was stuck in for a while.
You have a good base to start with, that's good. What you should probably work on now is working that style into something you can mold.
Right now, it more or less looks like you've trained yourself to draw one face, then put different hair on it. It's a good start, but in order to expand as an artist you'll need to be able to show different expressions, and different angles.
As cute as they are, all your ponies pretty much all wear the same expression, with just a difference in mouth position and shape.
Giving a quick browse to your DeviantArt collection, it seems you have a decent grasp of pony proportion, but you need to work on the 'flow' of the body so it doesn't seem as stiff.
I provided an example here, and I tried to mimic your art style as much as possible so this will seem more natural for you.
First up: Perspective. The main thing you want to try and do is understand perspective from a 3/4ths view. If you notice, the far eye is going to appear shorter than the closer eye, because that's how perspective works. You can see what I'm talking about by comparing A. and B.
Next part: Hooves. You have the right idea with them being shorter at the body and longer on the ends, but if you use a more sweeping stroke when trying to draw them you'll notice they look more fluid and less stiff, which is the example in the bottom left.
Third: Different ponies have different style eyes. I provided you three examples of three different pony eyes in a similar style to your own. You can see each is unique in it's shape and design. You should try to implement this in to define each pony a bit more.
Lastly: Expression. In the bottom right I've given you some example expressions done in a similar style to your own. Remember that varying pupil size works well for expressing emotion. Wide pupils normally are for showing happiness. Tiny pupils often express a shock or alarm. Also, if you change the shape of the eye rims, as the last example shows, you can also make the eyes feel more expressive of what is happening at the time.
These are just some examples for you to play with, based on my own personal experience. I hope they help!