I think you are already there. This is interesting work. White lady who wanders misty graveyard. Beautiful & effective mist. Thoughtful arrangement. Besides, what is necessary? /|:o)

Fishstar, this looks like a very nice start at a mood render or maybe a spooky one. PovRay is a great 3D app, and looks like you are making fog (Good as any Bryce can make!) using media, something way beyond my PovRay skills. If you are going for mood/atmosphere this seems nearly done. If you are going for spooky (Halloween coming up soon and all) you may wish to try an alternative were the fog is low to the ground, the idea being giving your transparent Vicky ghost more contrast near her immediate surroundings, making the gravestones and trees stand out. etc. You could also deside the time of day or night, and adjust your main sun or moon light to match, say yellow/brown/red for evening or blue/gray/violet for moonlight. That was the grond and tree leaves would not be a pale green, but would match the light you provide for the time you pick. You could maybe add a separate little light from below lighting Vicky's face, but only if you want that eerie effect. Almost seems this does not need the standard moon/bats/skeletons/pumpkins for Halloween, as it already has pretty cool scene content! Do not mistake me, I like this a lot (just as it as is!), just throwing ideas out to following up on your intro. Excellent WIP!