Got inspired by Arne to make my own take on your image, hope you don't mind.
Don't have anything in particular to say, but might as well just share a thought, or an opinion, now that I have posted.
When you're working on an image, always ask yourself why what you're depicting looks the way it does, what causes it to be this way; never let uncertainly rule over your art, if you don't know why something looks the way it does, or not sure how it is supposed to look like, don't improvise and slip it under the carpet, you will learn nothing from it; but rather take the time to study and understand it, this is the only way to truly progress (and with practice and dedication of course).
Arne addressed line art, and I have to agree that it is an extremely important part of creating art. I feel as if it is of the utmost importance to have a clear and readable line art before going into shading, colouring, etc. Tying it with what I previously said, when you create a clean and readable line art, you're basically forcing yourself from creating areas that you're not sure about.
Additionally, dedicating some time to first create the line art allows you to fix mistakes before they go out of control. I believe that you first have to be absolutely fine with the way the line art looks before you go into the later stages, as you did in your image - you completely changed the positioning of the arm; it might not be a huge deal in this particular piece (considering its size and all), but in my view this should never happen; once you have your line art finished, that is your guide for the rest of the painting, leaving room for only minor changes.
*I should really add that this approach with a clear and readable art line might not be the best with pixel art, especially when in need to make something rather quickly (I often start with both blobs of colours and a rough line art when creating pixel art, and then gradually refine it as I go along).
