I've always thought pickpocketing pulls alignment towards chaotic, I never realized it doesn't when you try to steal from already hostile monsters. So I decided to get it from the Thieves Guild and use it a bit to maybe get access to their training in the future. With skill at score of 1 it was very tedious, so I leveled it up to about 20. Since I was very lucky and found metal cap +4 very early on, I was basically applying Pick Pockets to every single non-friendly humanoid since experience level 4 (gained in a failed attempt to traverse SMC), failing a lot, angering them and training shield skill at the same time.
I'm now level 13 (drakeling assassin), recently reached Dwarftown. Pick Pockets raised from ~20 to 73 on its own with just my PC using it, no further points added. I also pickpocketed an amulet of life saving.
Holy crap.
I know AoLS was pure luck, but even without that, while a lot of monsters don't have anything with them, if they do have something, the chance of getting a potion, scroll, ring or amulet (especially first two) is quite decent, it's not only bones and small sums of gold. Along with AoLS, I pickpocketed necklace of rapid healing, a few resistance rings, potions of training and stat increase (both current and potential) and even one potion of gain attributes among others, with generally a lot more potions/scrolls/rings/amulets than I'd have at this point. This is pretty crazy. Was I missing on an amazing skill all this time? You can easily pickpocket from neutrals too, just kick them on Coward until they turn hostile, then do your job.
And another question - how does it work? Can you get any non-artifact of a proper DL, weighing 10 or less stones? I managed to pickpocket a torch and a leather girdle, but can you get blankets? Gauntlets/gloves? Bracers? Missiles? You could say that I will find out on my own sooner or later, but it's a melee fighter, I'm not particularly good at them and I expect to die soon.