[OPINION] Application of screen effects

[Damascus]

I felt like this would be the best place for this thread to go, but if it belongs somewhere else, please move it.

As I'm finishing up my mod, I want to make sure I'm being consistent with how I use screen effects, and what situation best suits them. However, I feel myself torn with how to use some of them. I'd like to ask the community, especially the veterans, what they feel are the best applications of these major screen effects:

IMAGE TRAIL - This one I've pretty much got nailed down as dizziness or sleepiness. Self explanatory.
RADIAL BLUR - I'm trying to use this one as a hallucination or dreamlike screen effect, since as in a dream, your peripheral vision becomes unclear, and you can only see things you are focusing on. However, if you seen an enemy, this screen effect disappears, and that sucks.
FIELD OF VISION - Since it narrows the field of vision, I'd like to use this one for when the player focuses on a particular object in his view, but I feel like it will suck the player out of the game due to the zoom effect being so apparent. Sort of undecided on this one.
SEPIA - I'm really not sure on this one. It makes a lot of contrast on the screen, so I'm thinking of using it in circumstances when the character is either really afraid, or his mind is playing tricks on him. It still seems like an odd effect though, even if I like it a lot.
ASPECT RATIO - No idea whatsoever. Any time I can think of having to use it is covered by GiveSanityDamage.

Anyway, what do you guys think?