I have few ratings, I don’t mark those Im not going to use but don’t throw away, as sometimes looking back at a later time they may pique ones interest. I have red for those to work on yellow for taking another look. However, after that I tend go through all of them, rate them and leave them to sit a while. Then at about a week later I would review. As to what I look for, for the rating. I look at contrast, is there enough contrast of light, is the composition balanced. Is it focused on what I caused my attention to shoot? Did I want everything sharp and is it sharp. Is there harsh filtered light I can’t do anything about and does it distract. Was it shot at the right height, angle. And most of all can it be brought to life, fixed in post (with my post abilities that I have). This latter point is why unless the image is awful, I hold on to most shoots (unless ththey are duplicated), because ones photoshop skills and technology enables one to fix them later.