On the Feux Follets and indeed any piece that requires intricate, tricky fingerings, my advice to myself and anybody else is to experiment with different fingerings and find out one that suits you best, then mark it down on the score.
I can only tell myself which fingering is best for me. I can't possibly tell which is best for you, however, because I don't feel how you feel. So my answer is - experiment, and device your own best fingering.
Some rules-of-thumb I would adopt on fingering:
- prevent impairment as much as possible on the musical flow
- convenience (to you, of course)
- as few turns as possible (ie, hand-over-thumb and vice-versa)
- make any leaps as narrow as possible
And mind you - never ever attempt to practise the Feux Follets as a whole. Break it into sections as short as possible - perhaps phrase by phrase. Relax while you practise.