How do I use mimicking miracles?
Step 1: Put a broken enhancement in Storehouse.
Step 2: Create a side battle involving your magician.
Step 3: Use Mimicking Miracles to copy said broken enhancement in Storehouse.
Step 4: Profit!
On a more serious note, Mimicking Miracles (when played on a magician) copies any enhancement in play. So if you attack with Claudia/Ethiopian Treasurer and play Reach of Desperation/Cup of Wrath and make your magician fight in the side battle, you could play Mimicking Miracles to copy Reach and Draw 3.
Or you could play it while blocking with a magician and copy an EE you already played earlier in battle, such as Two Thousand Horses, Every Man's Sword, Confusion (Prophets), etc.
Basically, any enhancement in play (doesn't even need to be evil) can be copied by Mimicking Miracles. This combos very well with Golgotha too.