Rose Merle Bertus
"Mixed Emotions"
http://www.nationalcollage.com/18thjuryexbi/RoseMerleBertus.JPG
Color is the dominant element with a strong contrast between the painted orange and black pieces of paper (plus the purple and green thrown in)
Teresa Garner
"Stamps, Markers, Etc"
http://www.nationalcollage.com/603PCS03/DSCF0070.JPG
Lots of pattern and repetition using the stamps. Plus the tomato provides contrast (color, shape) and dominance to the center. The round tan buttons also contrast with the square stamps and green color.