After becoming Cosmic Lords with my single-book spellcasters hardly maxed out, I figured my next Ironman party should do a little skill training just for the sake of it as early as possible...But the only methods working (at least with the latest patch installed) more or less well seem to be to cast heal at the monastery coffin (divinity, divine magic) and to cast charm on Arnika NPCs (mental, music).
Other than that, creating Hv.Heal potions gives me hardly one single point of Alchemy every 20-30 merges (which means resting for at least 6 x 8 hours), and casting knock-knock at the vault door only seems to boost earth magic, while wizardy goes up perhaps every 5-10 resting periods.
Oh, and all lasting spells like light/ench.blade/detect secrets seem to only train your skills about every 20-40 hours, *regardless* how often they are cast during that time!
Was all that easier without patch?!?