First Concept Art Tries - Custom Brushes

I'm now at the stage where I want to live out my creativity through concept and 2D arts too. I learn some drawing techniques and general skills within photoshop right now.
Those two pictures are my very first tries concepting an image with mostly custom shapes. These are free and bought shapes from many sources in the web. The images are far away to be good but I had much fun doing it. I learned alot and soon I will be able to bring these concepts to the next level with colors, right perspective and all that other stuff.

Thanks for viewing. If you have any tips feel free to comment. :)