I think the picture or cap you start out with has a lot to do with which effect or combination of effects works best, yes.
Indoors, outdoors, the mood of the whole scene, etc.
Of course you can always get right down to it and start erasing pixels and use smoothing and blurring and all that, but call me lazy. I've capped thousands in my quest for the right images for the PhotoCaps thread and probably, until I've got this film broken down into all of its separate frames I won't be satisfied. I know, I'm obsessed... LOL
But now I do have an awful lot of images to play with!

Vic