Hey, I am still a beginner and not a professional but from my perspective I think you are on a good path 
I really like how your background colours work together with your characters, I like the expression of the guy and the design of the last second one. one thing I would consider are the poses they look here and there stiff, especially the last one and the third from the start. In that case Gesture training was really helping me out with that. but yes they remind my of novel covers!
