Nice work David. Way better than my first pics.
I'm only a beginner myself but found that practicing to focus made the biggest single difference for me. I use a Bahtinov mask on my scope to help focus on Sirius. Once it's all in focus you can move to anywhere in they sky and be assured that focus is still quite good.
I made my own mask using this site ...
http://astrojargon.net/MaskGen.aspx?...ookieSupport=1 I'm sure you can do something similar for straight camera photography too.
Keep it up!