After an ungodly amount of time trapping souls and crafting daggers and stealing clothes and weapons to enchant, I have finally, finally got my Enchanting skill to 100. Now, though, I'm a bit puzzled as to how to proceed. I've snagged the last perk in Enchanting, the one that lets you bind two different abilities to the object that you wish to enchant, and I think that reducing the cost of both Destruction and Conjuration magic would effectively eliminate all of my magicka worries completely. However, I'm not sure what to enchant. Can you have four pieces of apparel equipped that will reduce the cost of a school of magic? Can you manage to get 100% magicka reduction with a paricular clothes set-up?

What you need to do its work the enchants so your covering all bases from different pieces. For example the chest plate can take the fortify & regen for two schools, then your hat can reduce cost further and provide quicker mana regen. That alone can give you 75% lower costs on your core school and massive mana regen rates from 4 enchants on two items. That still leaves you 4 enchants (gloves & boots) to refine your build.

Isn't mana regen only active outside of battle, and so fairly redundant? I'm thinking that reducing the cost of both Destruction and Conjuration would free up enough magicka to do anything else that I want, whenever I want.

Well some people say it is, but in my experience my mana regens extremely quickly in battle. I have a few high level spells I pop out to start with that leaves me at near zero and my mana comes back up pretty quick (level 27 150% regen ). But making it free to cast is the best route as you will never need mana again. My example is just that, an example to help you get your head around the doubling of the enchants.

You can get a circlet/hat/cowl/hood, robes/clothes/chest armor, ring, amulet all with a fortify school of your liking(must use grand gems with grand souls), and you have another extra slot to put whatever you want. On gloves you can put Fortify magicka and on boots some Resist.

Magicka only regens at 30% of your normal rate in combat, and not at all while you're actually casting. It's a very weak stat, and should generally be avoided.

Fortify can be enchanted to the following slots: head, neck, chest and finger. Assuming you've got 100 Enchanting Skill, all the proper perks (5/5 Enchanter, 1/1 Insightful Enchanter, 1/1 Corpus Enchanter, and 1/1 Extra), and Grand Soul Gems with Grand Souls in them, you should be able to enchant both Fortify Destruction (-25%) and Fortify Conjuration (-25%) to the slots I listed previously. That will result in free casting for those two schools.

Excellent, thanks to all for your help. Now I just need to do some quests to earn enough gold to buy Grand Soul gems!