I appreciate the nice comments guys, thanks
My workflow is such:
Sculpt various pieces in ZBrush at the full resolution - fins, body, teeth, tongue, lantern, etc. Though, the lantern was actually modeled in Blender.
Retopologize those pieces individually, mostly with ZRemesher to bring the polycount low enough to get a good, efficient UV unwrap.
Unwrap each piece, and take it into Substance Painter, where I bake all of the relevant textures from the high resolution to the mid resolution, such as normal, world space normal, curvature, AO, thickness, position, etc.
Use Substance Painter to create materials and textures for each piece.
Export 4 PBR maps (Normal, albedo, roughness, metallic), and import them into Blender, where I use my own PBR shader to utilise these textures in Cycles.
Position everything, use a nice HDRI to light the scene with some point and area rim/fill lights, render with a transparent background.
Take the final render into Photoshop CS6 where I composite a custom background with some matte painting and effects, and work on post processing, such as colour correction, tones, vignette, bokeh, adding low noise, sharpening areas, film type, and glare.
And we’re done! Hope that clears some things up.