A few things to make sure you guys are doing:
1. Make sure PBR is turned on (PHYSICALLY BASED RENDERING)
2. Make sure GI is on (AKA DIFFUSE LIMIT SET TO 1 bounce)
3. Motion Blur are turned on as well. (Motion Blur Checked on, Xform & Geo Time samples set to 2 for linear movements, and 5-8 for complex things like arms swinging/spinning, etc. 3 is a good default.
4. Make sure all your geo is being subdivided by defaullt. (in the geometry render subfolder of each piece of geometry check the "render poly as subd).
My process I learned from blue sky:
Light the environment first. Then the characters. If the environment doesn't look good, the characters won't have a chance. Render the environment separate from the chars.
The characters need all the focus on the head and eyes, you don't even need the environment in the character rop at all. Light it so the characters POP out of the environment. Make sure you don't leave the underside of the face go to black. It should be lifted w/ a bounce light. Eyes should be the main focus. Have a separate light for the eye spec hit.
Have 2 separate mantra rops. Env and Chars. Then have a 3rd mantra rop for character shadows (environment will have a new material on it only for accepting shadows, chars are set to phantom). The shadow render should be pretty fast in comparison since it only loads geo & 1 shader. If you need help figuring that out let me know.
Use Light blockers like circles (flat disk) or grids to direct the viewers eye to the characters eyes. Set the light blockers to phantom in the ROP. The other option is to use dappled lighting textures - set the texture map on the light w/ a map to make the lighting more varies, instead of a constant light, you get variation like what happens in real life.
I typically won't add color to my lighting until I have the values down. The values will be the true test if your lighting holds up, color only give it more life. Contrast/Value will be the key, so eliminating color at first will give your eye some room to see. Also, flipping the image horizontal or vertical is a great trick just like a painter, to reset your brain.
When I light I will do it one light at a time. Singling out the light will allow you to see what that specific light is affecting. I'll turn each one on, make sure each light is doing what I want, then turn them all on.