I got my Daedric armor to like 1500 by making fortify alchemy gear, wearing it and making fortify enchantment potions, using them to make better fortify alchemy gear, wearing it and making better fortify enchantment potions, and so on until I couldn't make better alchemy gear and enchantment potions. Then use the strongest enchantment potions to make fortify smithing gear and the strongest alchemy gear to make the strongest smithing potions. Then wear the strongest smithing gear to make the armor, and while still having it on, use the strongest fortify smithing potions while improving the armor. You end up with your main piece of armor worth like 20,000 septims (is there even a merchant in the game who can pay that?). You can make nasty-ass swords, axes, warhammers, etc using that method too. Also the enchantments on your weapons (even if you choose to make them strongest with the least number of uses) take forever to run out using the fortify enchanting potions constructed with the strongest fortify alchemy gear.