Being new at something doesn't mean I couldn't get creative with getting the result I was striving for. I had two challenges: Challenge 1:
Color of the background (BG) treesAt the time I didn't know about the power of light linking, so the wrap light gave the BG trees more light than necessary (and turning the them pink). To solve this, I used a cryptomatte and a grade node - one for the blue hue, one for the bit of pink. Additionally, to add dimension, a gradient was added to the trees - lighter at top, shadier at the bottom.
Once I revisited the project, after having more experience under my belt, I added the appropriate light links to the rig. This negated the drastic grading of the trees to the appropriate color in Nuke.
Challenge 2:
Replace the foreground (FG) of a beauty shot to avoid re-renderingI had inadvertently rendered a master beauty instead of the BG only after adding depth of field (DOF) in Maya. To avoid re-rendering, I had to figure out how to remove the FG in order to replace it with the updated version. This was accomplished with the merge (mask) and a cryptomatte.
You might be thinking, those are simple solutions, right? Well, I had only started to learn Nuke a couple weeks prior! By analyzing what I knew about masks and grading, I was able to piece together a script that worked.