I look mostly for photographic skill and good technique as well as composition skill. A photo does not have to be perfectly Sharp or perfectly 100% in focus if artistic or visual components outweigh technical shortcomings. Many times a slight technical shortcoming can be overridden by a picture that has a high degree of impact in other ways. Some types of photos however demand technical Perfection or nearly so, and it is difficult to describe how one evaluates a photo without 10,000 words to describe the process. Some photos are "vernacular" images, snapshots, if you will, and those are evaluated differently than serious Artistic Endeavors.