Originally Posted by ScorpioVI
4 pieces of armor/jewelry for smithing, plus smithing potions .
3 pieces of armor/jewelry for alchemy.
I don't believe there's any piece of armor/jewelry to enhance enchantment though. Best you can do is buy the Enchanter's Elixir (+50% Enchant).
You can't re-enchant an already enchanted item, or add another enchant to it even with the two-enchants perk.
If I remember right, I stumbled over some bracers enhancing enchantments 20%. I am too lazy to use them anyways.