黒人のナチ (Black Nazi)

[Boulsoup]

I've been experimenting with my drawing style for the past two months and this is what I've come up with. It's nice and simple. Please tell me what you think about it and how I can improve as an artist. What could make my future illustrations more interesting?

[TinyBird]

Well it looks like a pretty uninspired copy of the Adventure Time style, except it doesn't have the same form or flow to it:

I'd stick more practicing the basics rather than trying to create a style (copied or original), or if you want to use the Adventure Time style, actually study the animations and try to figure out what makes the style work and look good.

For non-style standpoint, this image has tangents and suffers from posing problems, like why is the character seemingly caressing his ear with the microphone? Not only does it look awkward, it creates a bad tangent, making it impossible to figure out where the mic is positioned (as opposed to if the mic overlapped the head line so we could see it's in front of his face).

how I can improve as an artist.

That has been covered several times in almost all of your art discussion threads:
http://conceptart.org/forums/showthread.php?t=234022
http://conceptart.org/forums/showthread.php?t=232889
http://conceptart.org/forums/showthread.php?t=231555
http://conceptart.org/forums/showthread.php?t=229128
Go read them again if you're not sure how to improve.