My method probably could be quicker, but it's not so bad if you're quick on the macros.
I use [Ctrl] mainly to go through a directory, with Light and Dark arts on Ctrl-9 and Ctrl-0 and couple of exceptions.
Main Directory (Also, essential spells):
Ctrl
[White Magic]
[Black Magic]
[Sublimation]
[Stoneskin]
[Equipment Change for MP Recovery]
[Target]
[Light Arts]
[Dark Arts]
Alt
[Attack] (reserved for any situation where melee might be useful, even if rare)
[Deo]
[Sneak]
[Invisi]
White Magic Directory (for each one, Ctrl-> Strategems Alt->Spells):
Ctrl:
[Main Directory]
[Cures] -> Cures, Regens, Raise/Rereaise
[Buffs] -> Protects, Shells, Blink, Aquaveil
[-Na spells]
[Weather Spells]
[Light/Dark Arts]
Black Magic Directory:
Ctrl:
[Main Directory]
[Elemental] (Separate book)
[Enfeebles/Drains]
[Helices]
Elemental Directory:
[Main Directory]
[Black Magic Directory]
[Earth]
[Water]
[Wind]
[Fire]
[Ice]
[Thunder]
[Light]
[Dark]
And an example of a magic directory:
Earth Directory:
Ctrl:
[Main Directory]
[Elemental Directory]
[Parsimony]
[Alacrity]
[Addendum: Black]
[Manifestation]
[Ebullience]
[Light Arts]
[Dark Arts]
Alt:
[Stone]
[Stone II]
[Stone III]
[Stone IV]
[Stone V]
[Sandstorm]
[Klimaform]
[Modus Veritas]
[Geohelix]
But I'll probably need to reshape them a bit just to try and make them more efficient. I find they work nicely if I'm working a single role, but they can be a little annoying when I've got to fill multiple roles.