Honestly I think you are progressing nicely. Tank photography is not easy at all. I've taken some good shots of outdoor stuff and pets and horses but my tank photography is mediocre at best. Lots of practice WILL make perfect...or at least much better...eventually.
Check out this simple tutorial, it might be helpful:
http://www.ximinasphotography.com/lessons/index.html
Check out this simple tutorial, it might be helpful:
http://www.ximinasphotography.com/lessons/index.html