First, let's talk about enemies and how they measure up defensively to the player.
Several times amongst this forum I've read that enemies merely gain health when held up against the player. Dragons, for instance, simply have a large health pool that the player has to wade through before getting the kill. So, the obvious, and maybe very simple change could be giving enemies additional armor (not saying we have to do obscenely hard scaling where a Bandit Chief has Daedric gear) and magic resist. A perhaps harder route would be to give enemies access to Perks that the player has access to. If the player has a Perk that can cleave through enemy armor rating, why not give the same to some enemies? Due to AI limitations it would be tougher to pull off things like enemies sneaking up on you for sneak attacks so we won't bother to offer that as a solution however I feel giving Bandits and the like the 20-60% more damage on weapons, or on armor, could make the game challenging despite the ways to grind out powerful characters.
Second, and this is probably the most creative way to handle difficulty, is giving enemies (and environments) access to spells the player has or perhaps even creating spells and effects the player can't use.
Let's touch on Chameleon Armor from Oblivion as an example.
100% Chameleon Armor broke the game, there's no question. What if though, to counter this and tip the balance back into a more even playing field, some enemies such as various level Mages, Vampires, etc, used Detect Life more often... or all the time? Certainly a player walking into a room invisibly would be taken aback if, after killing one enemy unseen, the Vampire Master turned around to face them directly and attacked while being able to follow your every move when you tried to hide.
In Skyrim Enchanting and Smithing are highly powerful, so perhaps a few ideas from D&D should be taken, more specifically Dispell and Null-Magic Zones. Not every enemy has to cast this, and not every local in the game has to have a set up like this, but it would certainly add to the difficulty if a Dragon Priest Dispelled your ward, or if some dungeons were protected with areas that negated all magic.
This could also include the ability to have more "status effect" spells that the enemy could use against you or be attached to wards. For example, Paralysis Wards like those found in Dragon Age, or more enemies casting Fear, Calm, etc on you or your Follower.
Thoughts?
