Hi Jessica,
I appreciate your sentence "It's clear I have a lot to learn."
Now you will find the ways..
With the ref. of your all conversation, you have to think some major points when you starting any work.
1. geometry(Polygon count or spline interpolation etc),
2. Shaders (Are you using the ready made material of VRAY?) if yes, then check- Is your material's interpolation value is higher! and other factor are really need you for super quality?!!
3. Lights: How many light you are using? Keep used lights only and delete others.
4. try to keep your scene file well managed!!
5. Play with renders settings.. Offcourse LC gives you gr8 output, but think of other.
As a Animator / Visualizer, We should do lots of study, RnD in respected areas... The most important thing is don't follow blindly to your seniors.. Ask why every time!!!