I'm not Bernard, but I'll make a couple of suggestions anyway.
In the loosest possible conception, all fingering is a matter of personal taste. You can play most of fantasy impromptu with your index fingers of both hands except for about 15 bars, where you need to press 2 keys at the same time, if you wish. But, doing this is going to be really really difficult.
For any fingering, do what you think is: firstly, most comfortable and secondly, best for the music, not neccesarily in that order.
Here are a few other hints on what to consider when choosing fingering. Try to keep the same fingering for identical patterns or figures. A pattern might be written with various chords, or in different modes. As for as possible, don't alter the fingering, this is so that you won't get confused when playing the piece.
Use fingering appropriate to the music. If you have to play very fast passages in scales or appegios, use fingering with less thumb under/over. If you have to play a legato or lyrical piece, you might consider using legato fingering. i.e. losely speaking, changing fingers whilst holding down a note.
There are some old schools that consider the forth and fifth fingers weaker and avoid important notes with these fingers. I think this is a problem more to do with technique than fingering per se. In general, I don't really subscribe to this rule. If you play mainly using your sholders, forearm and wrist not lift your fingers high, the last two finger should be as "strongs" as the others. You only need to keep the fingers firm and hold your hand in a natural shape, and play by rotating your wrist or trusting your hand. However, I do keep this in mind when playin staccato.
Choose fingering that will prepare you for what is ahead. Make changes like thumb over or thumb under at easy sections, so that you will not run out of fingers.
If you have large or small hands, you might want to consider fingering appropriate to the size of your hand. In general, fingering should allow you to relax as much as possible and not stretch you.
If you play repeated notes (the same note more than once consecutively), consider using differnt fingers to play each note. This is because although the note is the same, no two notes should should exactly the same.
I reckon that if you spend some time trying differnt finger you will soon discover what you like and what works. By all means use the stuff in the achieve as a guide, but don't be bound by hand and fast rules.
Remember, fingering is personal thing and you use it to to serve the music that you are playing.
al.