Hope you like my fan art

I'm looking back on my first pieces of art I submitted and realising how awful they are but they still get favs, some more then my latest work, I know I haven't submitted in awhile but I have exams So I'm asking my watchers for help, criticisms, suggestions, observations on what you like / don't like about my work. I really wanna try my best to make the best doctor who fan art I can or maybe you'd like me to draw something new, supernatural, Big Bang theory, Sherlock, game of thrones, just trying to get a handle on my audience if you can tell me a piece of mine you liked or faved, that will give me a good idea. I really want to know is it the detail? Is it the concept? Is it the style? Or is it just the episode or show that I draw which makes people fave them?

I know this is a lot to ask, but give the people what they want.. But I don't know what they want