Some sites offer head-to-head ratings; where two or more images are displayed simultaneously and the user is required to select the best.
Other features often include a facility to add comments, contact the submitter and view a profile of the submitter, and lists of new, hot or ugly pictures.
Sites with adult content should be submitted to the Adult category.
Sites which break the "best/most attractive first" rule should be submitted to Recreation/Picture_Ratings/Parodies
Pictures do not have to be of humans. Pet and car ranking are okay. However novelty categories (such as poo or riced up cars) should go in the Parodies category.