"Doran's" Jungle Enchantment Idea
With all the Jungle enchantments that give you stat boosts and passives that are well-suited for different roles, I think that a new jungle enchantment that buffs the version of smite you picked significantly would help further evolve smite into a summoner spell more prominent in it's usage outside of jungle objectives and ganking as well as allow more flexibility in both choice and playstyle.
The way I imagine it would work is something like this: Stalker's Blade Doran's Smite Enchant -Increases smite damage on champions by 100% -Increases Slow to 35%
Skirmisher's Saber Doran's Smite Enchant -Increases duration of effect by 1 second -Applies Grievous Wounds for the duration -Increases duration by 0.5 seconds every time target is attacked by caster, adding up to 2 bonus seconds to the duration.
Poacher's Knife Doran's Smite Enchant -Bonus gold from smiting enemy jungle increased by 10g. -Increases range of smite by 175 units -Damage against Epic Monsters increased by 5 permanently (as long as this enchant is in your inventory) every time you kill a monster in the enemy jungle with this smite.
Ranger's Trailblazer Doran's Smite Enchant -Missing HP and Mana restore increased to 22% -Increases stun duration against monsters and minions to 2 seconds -Increases damage of smite against epic monsters by 8%
These bonuses would allow each smite to become more effective at their role and all of them useful towards late game. While this isn't necessarily what Doran's enchantment should be, or what it should be named for that matter, but it shows off the basics and what I think would be an innovative addition to the game. Yes the numbers and effects may need some work, but the concept in itself is something to think about.