This is very refresh intensive but at higher refresh (submerged) you can have 72 (12 enchanted items with 6 uses) uses of 10 shift effects a session.
Even at lower refresh, you can mix and match your bonuses to drastically increase the effects.
Going from JediDresden's Lore 4 standard wizard, we have 1 specialization and 1 focus items free and we can take 2 points of refresh worth of refinement to work with.
We can start with 2 enchanted items at power 10 (4 Lore +1 specialization + 5 focus items) and 1 use per session. While 10 shifts is pretty powerful, 2 uses is not really that much. On the other hand, they can always be used again by spending mental stress.
Now we can go an take 2 focus item slots away. 1 we will put into another pair of enchanted items, the other one will be a crafting frequency focus. This brings us to 4 enchanted items at power 8 (4+1+3) with 2 uses each. Now 8 shifts is still pretty powerful, and the big difference is, you have 8 uses. And you have 4 different rotelike spells, so you can mix it up a bit, take different types of spells to be prepared for a lot of things.
You could even reduce the power on a few of them, if they don't need to be that powerful, and trade them in for even more uses per session. For example the 2 maneuver spell I mentioned above would only need 6 shifts, so you could have 1 enchanted item that does this 4 times per session with this model.