When I rendered my model with Cycles, it seemed to flatten out I noticed that when I rendered my model with Cycles, it seemed to flatten out. No matter how much more I rounded the model out, and no matter how I lit it to eliminate shadows, there was still a hint of this. I noticed what looked like other examples of this online. Is there an adjustment I should know about? Also, I tried to re-enter color and texture information and render with the Render engine but this does not work now. Did I change something by using Cycles that I cannot reset?
Is this the issue you have mentioned?

A flat shaded model without shadows as shown in the image below.



Check your "Ambient Occlusion" option under the tab "World". If you have set its "Factor" value to a higher value like "1" you will face this issue.



Try unchecking the Ambient Occlusion option or turn the factor value down to a smaller value like 0.05 or so as required. This might help resolve the issue.



Furthermore, darken the background color towards black, otherwise the model receive equal amount of background light from all angles.

Use multiple (about 3 different) smaller stronger lamps opposed to a large lamp. A large lamp will generate soft shadow and large widely distributed highlights. Small lamps generate well defined falloffs and concentrated highlights.