For Element Case's 2014 iPhone6 product launch, I rendered and retouched all case visuals for packaging.  
My retouching steps, above, from left: Composing, Texturing, Lighting, Detailing, Adding dramatic hot white surface hits, and Fine-tuned brightening.
My process began with obtaining a custom version of the product CAD file to be outfitted with micro-chamfers, micro-filets, etc. These improvements allow for super realistic renders, avoiding what we called in the studio 'rendered video game asset' syndrome - flat and unrealistic visuals. From there, I added and tweaked texturing and lighting to match the product. Next came detail editing, adding dramatic hot white specular hits, and finally fine-tuning brightness for a dramatic final effect.