Let's break it down:
Thaumaturgy Crafting spec gives you either a +1 for frequency (increasing uses per session) or strength (increasing item potency by 1). It's under Crafting in the Spellcraft chapter. It's a rules exception; you know how that goes.
Let's say you take strength.
You have Superb Lore.
That means any items you specify will have a base strength of 6 shifts. (+5 Lore, +1 spec)
You have a potential 4 enchanted item slots from Thaumaturgy power, if you take no focus item slots. Let's assume you pour all that into one item.
You use one slot to make your armor, and pour as many slots in as possible. So you make it 8 shifts, divided by 2 is persistent 4.
That's Armor:2. (Check out evocation blocks - armor rating happens at a 2 for 1 rate. Hence, armor stuff is halved for persistence, and halved again for effect. There's an example item that shows this as well.)
Because you wouldn't get any benefit from adding that last shift (9 shifts goes down to persistent 4 as well), you keep the last shift.
Either that means you have a potion worth 6 shifts, or you can specify another enchanted item with a once-per-session, 6-shift effect.
So, Superb Lore and Crafting Strength spec and all slots spent on items gets you one set of Armor:2 and a 6-shift potion / other item.
***
But let's go crazy, and say you used your evocation focus item slots to make an item that helps you with crafting. (It's legal, don't look at me that way.) You have to, by default, adhere to the columns, so you get +1 frequency and +1 strength.
All that would mean is that your armor had a base strength of 7 shifts when it started. You could invest all your slots for 10 shifts. So it'd give you a persistent Armor:2. (Remember, halved for persistent and halved again for armor.)
You're smart, so you only invest one slot and keep it at 8, for Armor:2. You now have two enchanted item slots. That's either two potions, two enchanted items that are once-per-session at a strength of 7 shifts, or some other legal combination therein.
Max combo ends up being one set of Armor:2 and two potions or enchanted items.
It's late, and I'm tired, so please let me know what part of that didn't make sense.
[EDIT: I caught one that didn't make sense to me already - blocks by nature cannot be persistent effects. So if you're going permanent, Armor is your only real option. Oops! (There might be another thread about this later, true believers.)]
-Lenny