I like the mood, really, but the designs are not so good. I think you're having an hard time learning to design, learning the design (which is different) and learning to paint all together. You must start working on the design process with simple tools and in black and white or monochromatic scale focusing your effort on the design itself and slowly on the painting technique, if you do all together it will take a life to learn how to paint cause you're always distracted by doing the design and your designs will never feels good cause are presented with a muddy and unfinished look (even if they may be good, the aspect is a priority).
First rule: if it's not a sketch... don't repeat lines!
I'd appreciate it if you could elaborate on why the designs aren't good. Is it the fact that most of them don't have crisp and defined lines? I also start all my designs in black, white, and grey. What is your normal method while designing?
Cause all of them are not finished, or it looks like they are not finished. The fact is that if you present you work in a bad shape it won't work, never. You need to improve your design workflow, learn how to cut it into steps, learn how and where details are important and what kind of details are important.
Lots of people start to design in black and white but i think it's very confusing for starters cause you have the cave dark from one side and the sun light from the other, are you able to know how to manage 98 shades of gray in between? Of course not, not so much people are able to do that. I think the bnw is a good way for shaping silhouettes but very hard and confusing to do a real design on it.
I don't have only one way to do things, it depends on how i got the design, sometimes i go with linework then i elaborate the design (the common way), some other times i use silhouettes and then i work over the shape, some other time i start the design directly on drawing what i need (only if i know the topic very well).