Setup
I'm not a setup expert, but I wanted to pose the character for the final render, so I created a biped with the size of Goofy and applied a skin modifier to the different parts of the model. Then I fitted the envelopes to match the model, so I could pose the character (Fig.09).

Fig. 09
Lighting
Although Goofy is a cartoon character, I wanted to achieve a realistic illumination, so I choose mental ray as I said before. I used two area lights (photometric) with an angle of 45 degrees off the camera; this way I was able to add volume to my model. I did not use Global Illumination because Final Gather worked just fine for me in this case. Final Gather presets usually works fine to me, so I just made a couple of changes to achieve the final result (Fig.10).
I did two renders. In this case I did not want to add Zdepth to my final image, so I just did a beauty and an ambient occlusion pass. I wanted to create the background in Photoshop so I rendered Goofy over a matte/shadow plane to keep the shadows on the ground.

Fig. 10
Post-Production
I took these two render passes to Photoshop. I then put the ambient occlusion pass over the beauty render in Multiply mode with an opacity of 44 because at 100% the model looked too dark in the occluded areas.
Finally I added the background (a circular color gradient) on the bottom of the layer stack and a few layers over it to control the final curves, exposure and brightness and contrast of the final image (Fig.11).

Fig. 11
And here's the final image (Fig.12).
Fig. 12
Final Thoughts
As a conclusion, I would to thank the guys at 3DTotal for including my image on this great site and for giving me the chance to share my thoughts about my render on it. I hope some of these tips can help you in creating your renders.
If you have any questions or comments feel free to email me.
Thanks,
Jaime
"Do everything by hand, even when using the computer”
Hayao Miyazaki