Stone
- Hold to grab or attract loose rocks.
- Drag and release quickly to throw.
- Compress to melt.
- Expand to explode like a grenade.
Fire
- Drag and release to throw fireballs.
- Expand to create a weak area-of-effect burning sensation.
- Grab and hold to wield a flame.
- Compress to extinguish.
Metal
- Grab and hold to wield discarded weapons.
- Compress to squish armoured foes.
- Grab and pull to tear the hinges off doors.
- Push with a wide focus to repel enemies.
Souls
- Grab and pull hard to sever the soul, killing the victim.
- Compress to stun quickly.
- Expand a grabbed soul for an area of effect stun.
- Grab a bit of your own and put it into a fresh corpse to gain a minion.
Those are the four I've worked out so far, though others may certainly be possible: light, shadow, flesh, wood, etc.