If you wanna be better at drawing, you should start learning the basics more. And, if you wanna be better at it, start by having a simple art style. Take Nichijou for example, it has a really simplistic art style.
I ain't an artist. Heck, I don't even know how to draw hands correctly, wich is why I never make them on storyboards. But I know how to at least give some tips.
You should try more positions in your concept arts. If you wanna see a simple example, take a look at those concept arts for the Nichijou anime :
It's simple, with really basic positions, from the back to the front, with a close-up and all the good stuff any artist should train for.
So anyway, keep training yourself. You're on the right way. Just keep doing more concept arts and other drawings to train yourself. That's all I really have to say, maybe @
TJ-Works
has more to add.
Good luck my friend.