Having judged photos for over 4 years and having taken photos for over 30 years, I feel qualified to share some insight to what people who judge photos are looking for.
1.) Have a dominate subject or theme . . . that doesn't mean it HAS to be a single subject like this, but if you have to guess . . . that's not a good sign.
2.) The Simpler the Background the Better . . . that doesn't mean it HAS to be soft focus like this, but do NOT let it pull your attention away from the subject.
3.) Lines and Shapes Must Support the Subject . . .
too often and lines or shapes can lead your eyes off the page and or make you wonder what else is there besides the subject.
4.) A Great Image must have Emotional Impact . . . we all see 1,000's of images a day. The Greats Ones are those that stay in our mind. We can feel, touch, or smell that image in our mind because of the creative use of Texture, Depth of Field, or the Rule of Thirds. Great Images make us want to look again and again. Not all Artists are Photographers, but all Great Photographers are Artists!! Be aware of the Principles of Design. The Photo seen here was shot by Janet Daniel from Texas. It did not win our photo contest when first submitted, but . . . it easily could have.