First of all, very cool stuff. You have a sensibility for a design aesthetic specific to you, as in I wouldn't confuse your stuff with someone else's very easily.
It feels like you have all the tools you need, you just need to focus and implement them a little more. I know these are sketches, but it might be helpful to lay down a clear objective of what you want out of your next piece, and work to achieve that.
A pleasure to look at.