Ways to achieve unity

Repetition

The pattern in this design is repeating thus showing repetition in the design. 
Repetition: The same visual design repeated over and over again. 
"Interview: Patty Young on Mezzanine." True Up. Patty Young, n.d. Web. 10 Sept. 2012. <http://www.trueup.net/2009/fabrics-2009/interview-patty-young-on-mezzanine/>.

Proximity

In this image the girl in the dress is closer to the camera than the people in the background. The placement was put like that on purpose to the girl would be the focal point. 
Proximity: The degree of closeness and placement in an image.
"Musings of the Urban Chic."ʉۢ Fashion Photography 4. N.p., n.d. Web. 10 Sept. 2012. <http://sweetlomiranda.tumblr.com/post/29085773498/fashion-photography-4>.

Continuation

In this design the stripes in the shirt are continuous and makes the viewers eye follow.
Continuation: Something continues, a line, edge or pattern. More subtle than proximity or repetition. "Collection of Casual Formal Clothes and Accessories » Blog Archive » Oversized Tee Dress with Lines Motif and Beads by Shakuhachi." Collection of Casual Formal Clothes and Accessories » Blog Archive » Oversized Tee Dress with Lines Motif and Beads by Shakuhachi. N.p., n.d. Web. 10 Sept. 2012. <http://www.fashioncollec.com/oversized-tee-dress-with-lines-motif-and-beads-by-shakuhachi/>.