Grim Reaper Weapons
The Drain Health enchantment is a powerful way to create instant kill weapons. With a Grand Soul Gem you can create weapons which drain 50 health for 3 seconds, 90 health for two seconds and 100 health for one second. At levels under 25, this will kill just about anybody instantly. They only have around 20 uses, but with a decent supply of Varla Stones, Soul Gems and assuming you're near a recharger, these will serve you well. You can also create an armory's worth of these weapons so that you won't run out mid-combat. I've found this enchantment works especially well with bows.
Skill Boosting Gear
Same principal as the Camo Gear. A Grand Soul Gem boosts these skills by 10. In other words for Acrobatics, you can have a full set that is as good as the Boots of Springheel Jack.
Money-Making Strategies
Arch-Mage's Chest
Upon completing the Mage's Guild quests, you can use the Arch-Mage's chest to multiply a single alchemical ingredient. The most obvious application is to sell back ingredients, but there are some truly effective ways to make this worth your while.
Upon completing the quest Order of the Virtuous Blood, you can sell Vampire Dust to the leader for 250 Gold a piece (it may be leveled, I'm not sure). Vampire Dust falls under the category of alchemy, so that means the Arch-Mage's Chest will work. Putting one in the chest and waiting overnight will result in 10 additional vampire dust appearing (i.e 2500 extra septims a week in your pocket).
Also, during a certain Fighter's Guild quest, you gain access to a woman in Leyawin who will purchase Ogre's Teeth and Minotaur Horns (both of which are alchemical ingredients). She buys them in sets of 5 and the money is not as good as the vampire dust strategy above, but it is still pretty useful. Be forewarned, though, that minotaur horns are heavier than your usual alchemy ingredients.
High-Level Looting
It is common knowledge that the higher your level, the better the loot. And the best place to go looting is in those Oblivion Gates. Completing even the most basic gates will send you home with at least 12,000 Gold in Daedric gear (assuming you're level 22 or higher). If you don't want to risk the traps of Oblivion or if you've already completed the Main Quest then another excellent place is Ayleid Ruins. Forts are next in line. Caves are usually the worst for natural loot, but their inhabitants may have valuable armor and weapons.
Master Thievery
With the Camo Gear (see section 4) it is possible to pull off some truly elaborate thieving. As mentioned, you will have negative effects for looting areas that have a faction affiliation that you share, but here are some hot places.
All of the Castles are obvious targets now that you are basically invincible. Castle Bruma, Cheydinhal, and Skingrad are your best targets, because they contain some of the best treasures. A daring individual may even attempt stealing from the count and countess's themselves, but you'll need a fairly decent Sneak skill to accompany this.
If you're not a member of the Mage's Guild, the Arch-Mages tower is a good place to loot. If you are a member then you may not want to risk losing your membership. If you're the Arch-Mage then take whatever you feel like in broad daylight. It's your stuff.
This really isn't stealing, since the only way to access this area is to be a member, but the Cheydinhal Sanctuary for the Dark Brotherhood has some decent loot. It's best to hit during the Purification mission. Also, when you've completed the quest line, stop by once a week and kill the Dark Guardian and steal his weapon, which is usually semi-valuable.
The Imperial Palace is the setting of the Ultimate Heist Theive's Guild mission, and you can find some decent stuff in the regular area's as well.
