3- Arcane Casting
Smell the magic
I'm a fan of casters of all flavors. The ability to manipulate -other- forces in the universe is a fascinating thing to embody.
But, one of my favorite "magic" abilities, was that somehow, it became a joke that one of my Bards could detect magic via olfactory senses. It would result in various schools having aromas with a plethora of notes depending on caster, alignment, and resulting spell.
It became such a prevalent house rule, through most of 3.5, across multiple Groups (and into Pathfinder, if I recall) any full or half-human with the last name "Dansin"(or at least this bloodline) had to burn a/take the feat to gain Detect Magic if they didn't have it from the class, to denote this heritage (Arcane Talent for Pathfinder & Mystic Atunment? for 3.5)
Every so often it still comes up, asking if it *sniff sniff* reeks of conjuration, *big inhale - cough * Illusion. *gak*