You may have heard this critique of Saving Throws in D&D and related games in the past "the saving throw categories are just random, illogical and incomplete ". My answer...Change them.
That's it, come up with your own saving throw categorizes if you can't bear the ones that come with the rules.
There are three good reason to do this in my book: 1 you just can't stand it that staves and wands are in two separate categories, you are a totalist who needs everything spelled out or you just want your current campaign to feel different from campaign X (the last is the best of the three reasons really).
A Revised List of Saving Throw Categories (for a different Feel):
Bindings, Runes, Symbols and Power Words:
saves versus magical compulsions, elder symbols, wards and spoken words of true power.
Glammer, Deception and Phantasms:
saves versus minor magical trickery, shady misdirection and illusuinary influences.
Elemental Forces, Gases and Exposure:
saves versus Dragon Breath, Fireballs, Noxious Gases , Freezing cold and Searing Heat.
Petrification, Transformation and Confinement:
saves that would change ones form, shape or physical freedom.
Necrosis, Poisons and Paralyzation:
saves versus Death, Mummy Rot, Poisons (Ingested and Injected) and the Paraylzing Touch of Ghouls.
Passion, Ill Humours and Domination:
saves versus emotional assaults, diseases and other effects related to the humours and mental domination.
There is certainly some cross over on these categories. I recommend one go with the source over the effect to determine which save category to use.
Magical items, charms and player precautions may provide a bonus versus a single subcategory but generally shouldn't involve the entire category.
The above list is just a suggestion, not dogma. Feel free to ignore it or more hopefully be inspired by it to work up a list of your own that will develop a unique flavor for your own games.