Xeviat
Dungeon Mistress, she/her
As for a rangery counterpart to Paladin smiting; two ideas:
Infuse Trap. Make a snare or place a bear trap. Spend a slot to make the trap magical. Since trap damage is way less direct or assured than smites, damage should be way higher. I suggest three times as high, meaning 1d20 (instead of 1d8) plus an extra d20 for each higher spell level. Plus 1d20 extra against your favored enemies (mirroring the smite undead bonus).
Idea 2: Infuse Poison. Much like a smite, spend a spell slot for extra damage, in this case 1d12 poison damage. At maybe level 12, gain ability to infuse psychic poison for +1d8 Psychic instead (since far too many high-level foes are immune to poison).
This way, if you care about DPR you can pick the Ranger. If you don't care about DPR, nothing will have changed since you will keep casting the actual Ranger spells.
I'm still very tempted to remove Hunter's Mark and Hex as spells and make a version of them into Ranger and Warlock features. I like the idea of expending a spell slot to mark a target, gaining some benefits to tracking them and also dealing more damage with attacks against them. I'd rather see something like that for an equivalent to Paladin smiting.
Finding the balance point would be tough, though.