of course. thanks for your help ~
- i feel like her mouth shape is a bit odd, but i tried countless times to fix it but this was as good as it could get
- not sure if this is just me, but her left forearm and hand looks too small compared to her overall size
- the shading is too plain in some areas, but i didnt know what to do there (like her boots, tights and skirt)
- her boots also look odd, but i can't seem to figure out what i did wrong there
Ok great
As for the mouth shape, the bottom lips point inwards. Taking Mirai from your sig as an example, you can see that her top lip is drawn a lot more straight then the bottom which curves inwards more like a semicircle
The size of the forearm is straight however her hand is very small. A spread palm should roughly be the same size as the face
The way the forearm connects with the elbow is a bit strange -
this is a good graphic to see what an elbow looks like - and as you can see by the protruding bone from the forearm the angle is more like a right angle than a curve
As for the shading, don't be afraid to use dramatic colours. The same shadow colour should not be used on the top of the head where the light is hitting and in the area around the neck where the light can't hit it. Try to use 3-4 tones minimum with shading (2-3 dark and a highlight, you could add 1-2 accent shades too). You're going to end up using colours that might look way too dark for the base colour, but once you blend it in it will seem a lot more dynamic.
With the boots it's just that the feet aren't facing in the same direction as the rest of her body (forward while as the feet are on their side)
In general it's just small errors with proportion and the shading seems somewhat flat
If you're not doing this already you should look at references. To get better at drawing people will tell you to practice and practice and practice. They're not wrong, but one thing that is just as important as practicing is
looking. Go to your favourite artists' gallery and study their pieces: how they've drawn hair, the colours they've used to shade...so on
You're definitely on the right track though! Hope this helped and keep up the good work