Double exposure is a photographic technique that makes two pictures into one picture. Black and white photography creates a feeling of timeless emotion. Sepia is a specialized treatment that gives a black-and-white photograph a warmer tone. In emphasis it is the artist making part of the artwork stand out, to make the viewer's eye look there mainly. Silhouette is the image of a subject outlined or filled in darkness while it is surrounded by light. Boat'n Hand is a type of optical illusion that through the camera's placement makes the figures in the picture make a perspective that is visually interesting.
Also, the rule of thirds is when you break a picture by thirds as in lines into nine pieces the viewers eye's go to along the lines or the intersection of the lines.