Some Basics?

[Ploaj]

I made some slight edits but I can't get the legs or hair to look right.

Any suggestions?

[StarSock64]

More contrast everywhere!

I think you should focus on shading the hair according to the light source before adding a highlight. You might want to find a way to make it look more outlined, too, because it's kind of weird how it just blends into the face like that.

The torso could really use more space. Maybe widen up the shoulders and make it a little longer so the rib cage can get some room in there. I'd help you with the legs but I'm no good with legs either, so um, maybe try to find some references or something. I like to kind of define noses like that in sprites too, but with anime characters like this, where their noses are really little if they even have any at all, you should just omit it.

edit: Okay, I'm really out of practice, but I decided to give it a try anyway.



I was going to actually properly shade it, but um, that didn't happen. When I sprite, I prefer to make things simple and just block out colors like this at first. It helps me get bigger and cleaner pixel clusters, since it can be tempting to try to shove in a bunch of little shades here and there. Come to think of it, the tie would probably be better a pixel longer because it's kind of running parallel to the shirt, and that's not really working out. I wish I could shape it better or something, but since it's 2 pixels wide, that's not much of a possibility.

[Ploaj]

I wondered why the torso looked so weird.
Looking better?

[Proton]

Your light source on her left arm makes it so there are 2 light sources, and you may as well just make the leg's skin colour on shade.

Work some AA into the hair and tie,

and then work on removing most of the black lines on the inside of the body (the lines between arm and blouse/vest/shirt/whatever, the collar, tie, shirt flaps)

[Ploaj]

Made some slight edits but I forgot to put any AA in the hair.

[Cobalt Blue]

at that size, a proper palette would be better than Anti Aliasing.

[Frario]

I must say the last edit looks the best, so i'll disregard everything from before.

Honestly, why not suggest Ploaj both solutions : a good pallete and anti-aliasing?
To me, Vocaloids have a very elegant thin (like almost anoreic teen) body. This feels a bit chibi for the typical Miku. She always looks tall and thin. So maybe slim her down by a pixel?
Thing you gotta work on though : hair. Try adding some 'strokes' that go up, starting from the bottom. think of it as 'grass' sprigs.