Our fiber art group project was to use line in an art piece somehow. This is how I used it: I used thick black semi-diagonal lines to create irregular rhythm and grouping, I used the stitching in between the lines to create shapes, and I used the scribbly lines in the circles to create dimension and value. My color scheme was analogous, with the exception of the black lines, as the piece ranges in color from red to yellow and red to fuchsia in the stitching.
Check the other page on Fiber Art Group Studies to see the piece before stitching. For the round balls that look dimensional, this is how I achieved that effect: I placed a piece of silk organza on the back side of the red fabric where the circles were and then placed the piece in an embroidery hoop and stitched it. Next, I hand basted a piece of wool batting to the back side of the circles before I put my layers of backing, black Hobbs Heirloom batting, and top piece of fabric together.
The reason that I do this is that it enables me to leave areas unquilted and still lay flat without any unsightly puckering. You can see how smooth the transition is from the heavily stitched area to the densely quilted area. Also, by using the silk organza I added minimal weight or rigidity to the top layer of fabric, and now I don't have to get the piece wet to dissolve either my stabilizer or any water soluble thread. There usually is a method to my madness, and of course you do have to be at least a little bit crazy to do this kind of stuff to begin with.