Glad to see you're trying to add more details/effect in your artworks! :D
The main issue needs to fix is the part where judal and Aladdin's hair are overlapping, there are many jpg
artifacts, maybe you didn't colored there properly, please fix it and update the wallpaper ASAP because it's
ruin the quality of vector so much!
I'm mainly gonna comment on skin and hair, the skin of Aladdin especially his face, the shadows and highlights are
looking like he is in a dark room or cave and a candle is lit in front of his face, especially those small highlights
below his eyes, and the shadows of whole body are too dark for that all bright BG, try to lower the opacity/fills of
shadows' layers. I think you've used a complete different color shade for coloring his skin's shadows and
highlights right?
I now rarely do that, I just use the same color as the base color and change the blending mode. (most of time to
"multiply" mode) and then just change the opacity/fill of the layers to made them blend with each other.
And as the scene is too bright, you should have used gradients on base color layer too, it's simple just open layer
properties, click on gradient overlay, choose the gradient style of "Color to transparent" and add the color
of base and use the "Multiply" blending mode in gradient for shading and use the "screen" blending
mode for highlights, play around with opacity and scaling and gradient style to Linear, radial etc. I mostly use linear
for skin.
I'm sure it will definitely help you to color skin better with all the gradients! :D
And then hair, again Aladdin's hair look too dark for the BG, to fix this issue use the same trick I mention for
coloring skin. And yeah it's just a personal preference, that I don't like outerglow in shading the hair,
because they ruin the crispness of hair (For an instant I thought that braid of Judal are some balloon like things).
It's obvious that we can't make every single hair strand in vectoring, it'll take ages to have skills and
speed to make them like that, but we can make hair crisp to at least make them like hair, outer glows sometimes looks
good on brightest highlight though.
And if you can't work well with gradients, then try using atleast 5 layers for shading; 1. Base color, 2. shade, 3.
Dark shade, 4.Highlights, 5.Too bright highlights. (you can even use more to give depth to your arts)
As for lineart, you still need in practicing more, because there are some parts too thick and some too thin.
And the foot of Judal is not looking like a "Foot" at all, make fingers in his foot.
And the overall atmosphere is too bright, and as the characters are not looking bright, it makes the lighting of whole
wall off.
Try to imagine the result of your plan and then work on it, if you feel that you're stuck in midway ask for advice
to any active artist here, we all are ready to help.
I hope you'll improve more in your next work, keep your good work up!