Don't be deterred by my negative ratings, it's just that we've all seen a million devs like this.

However, I see your potential as you seem to be skilled in drawing the general shape and flow of hair, even incorporating single strands and picking out sections. Kudos.
You also have a basic understanding of the contours of the neck, which i enjoying seeing in budding artists.

Now, what gets me if that you're using MSPaint by the looks of it. Paint does no one justice. You're best taking a traditional medium for better effect or, if you're really wanting to do digital art, then get photoshop, GIMP or Corel. Then you can expressed the dips and peaks of the human forum.

Another thing which I think was mentioned before by a critic was that you seem to cut off any evidence of a body. Are you maybe a little nervous? No worry, sweets, you should just have a go and really practise with each picture. How about cutting figures in different poses from magazines. Even if you enjoy the manga style, I advise looking at the real body first, just to nail proportions. Remember, no one will bite you for having a go! That's what the critique feature is for. Good deviants will help you out.

The sparkles... Hmmm, i can see what you're going for, but they're too uniform and they clash with the background colour. If you're trying this effect, try to make the sparkles less same-ish. If you get photoshop, you can make up your own brushes and use the settings to help you scatter and vary each sparkle.

I hope you found this helpful. Don't be afraid to drop me a note if you have any questions. Have a nice day.

the face is well done, the eyes are very expressive, and your shading around the edges of the face has been done pretty well. there seem to be alot of things your avoiding though in this piece, which might be hindering your development. you covered up everything bellow the neck with her hair, and it giving the portrait floating head syndrome. its also something people do alot when they really want to draw a face, but aren't as comfortable with the body, but its a device that rarely works. I would also try to give the same kind of attention in terms of shading to the hair that you did to the face, and definitely get rid of the photoshop brush neon starbursts. other than that just keep going and make more. you have faces down, so really challenge yourself to draw the beggining of the torso and things with the same precision you did the face.