Myself and many believe that a good image is not only technically correct, as a example (good exposure, good depth, with some sort of composition) but also going well beyond; an image that expresses something about the scene, or about what you felt as you took it, making it more than just a good snap shot, making it a work of art and passion.
All the images on this site are photographed in one shot, none of been modified by adding a layer in photoshop, they are just taken at the exact moment when it is happening. With the moon images you have only but a minute or two and then its over, with the twilight there is 10-15 minutes of perfect light.
Learning to recognize a great shot is going to happen right before your eyes is usually your biggest hurdle to being successful.