Ooh, I agree! The Luna drawing is quite spectacular. But I feel like I need to quote Cupcakes14 here.... So I will.
What he said right there is SO BEYOND RIGHT. Free hand is difficult, yes, but with lots of practice, you'll get the hang of it. And just to echo him.... Proportions are sooo imporrrtant. I too am an artist of sorts, and around a year ago, whenever I would do fanart for MLP, I would always get the neck proportions wrong. It looked fine at the time, but looking back, I want to cry. Unfortunately, it's just something that comes with time and lots of practice, as well as free handing it, and just throwing things out on the page in your own personal style. HOWEVER, you have a very solid starting, and I just simply cannot wait to see more from you! Keep up the good work!