This is a very simple trick that allows you to equip multiple shields. You can stack enchantments like this by simply enchanting a couple of light shields to your liking. And the best part is that you can simply unequip the extra shields at any time to undo it. The extra shields remain invisible.
All you need for this is some shields (enchanted or not) and the Bound Shield spell:
- Equip your 1st shield of choice
- Unequip your weapon
- Cast Bound Shield
- Equip your 2nd shield
- Wait for the spell to wear off (or wait an hour)
Once the spell wears off, you will have both shields equipped. You can repeat this infinitely to equip even more shields. The shields remain equipped as long as you don't manually remove them and even if you do, you can simply reequip them without repeating the setup. The extra shield slots you gain remain usable. You can change which shield to display by simply unequipping and reequipping the shield you want to see.