I was thinking for locked doors it would be:
Warrior: door bashing, attracts a lot of attention
Mage: magical key. Like it appears in your hand and you open the door.
Stealth: lock picking obviously.
Another example of this could be how you get around. Like when faced with a rockwall where your objective lies on the other side.
Warrior:climb up it slowish
Mage: levitate up there
Stealth: some sort of grappling hook or zipline.
So what do you guys think?