What skills can I advance while I'm away from my keyboard?

From The unofficial Elder Scrolls Pages:

"You are also able to level up by increasing any skill, not only those you are focused on, so > accidentally power leveling to beyond your means in terms of gameplay is possible."[1]

So this way of increasing your skills might not be the best idea. You decide.

All Armor skills and block using... Slaughter fish!

Stand in water, equip armor type you want to raise, go afk.

I highly recommend you drink a health regeneration potion, as slaughter fish CAN hurt.

I will admit I have yet to test this, but it worked in other elder scrolls games, and in this one, armor has no durability... so afk seems fine. I have encountered slaughter fish in lakes, and they didn't do anything but startle me when they attacked. No real damage, but that could just be luck. I was wearing leather armor (fine) and had under 20 light armor skill at the time though, so I assume it is save as ever.

Confirmation will come tonight, unless someone else verifies before then. But I've used this in other ES games, and their damage in this one seemed low enough to do it in this one.

I know in Bleak Falls Barrow (one of the first caves in the game, where you get the Dragonstone), there's a waterfall leading from a room overlooking a path, and a Draugr patrols that path and the room overlooking it. If you jump down into the waterfall and land on the stones beneath it, you're out of the draugr's reach, so it can never find you. If you crouch and sit there, you can get sneaking to level 100 over night. I'm planning on creating a new character so I can exploit this and get all my leveling out of the way by resetting Sneak a few times.

I know Sneak has a lot of other exploitable gain options, but this one is 100% automatic and doesn't need anyone to be asleep

Restoration: If you have a 100% less majicka enchantment for restoration, and use an elastic band to hold down dual-casting healing, you can just stand in front of low-level enemies to level up. The enemies will slowly chip away at your health, and you will continue healing/levelling restoration. Alternatively, cast equilibrium opinion in one hand, and healing in the other.

Sneak: Go to Dragonsreach, go upstairs, turn right, and go through doorway on to the balcony above the main area. Sneak, and use an elastic band to keep your character running against a pillar.

Block + Armors: For block, use an elastic band to hold down the block key, and for armor, just equip the armor type you want to level. Stand somewhere where you can only be attacked from one direction, ensure this is the direction you are blocking and wait for enemies to attack you and level you up.

These may take a while, so just leave them on overnight.

You can level Sneak, One handed and Two handed AFK/AFC before you leave Helgen at the beginning of the game.

Sneak -

One and Two Handed -

You can also level Pickpocketing to 100 before leaving Helgen

The guy with you won't stop you, just save after successful steals.

You can easily get infinite money by going to a chopping block and afking there overnight to get a bunch of wood, then sell it all to get a ton of money. I recommend selling it at a lumber mill because it gives you more money then selling it at general goods and you don't need to reset their inventory. Using that money you can also buy training and buy things leveling up your speech.