If you're only casting one half of a fuse spell, you declare which half when you put it on the stack
In any set that includes them, they make up the most expensive cards that you can pull
You ignore any timing restrictions based on the card type of the card you copied
Marketplaces like eBay have a filter that lets you view only "Sold Items," which is an invaluable resource
Excluding the "Hieratic Seal" Main Deck monsters, the "Hieratic" Xyz monsters, and "Hieratic Dragon" of "Sutekh", "Asar", and "Nuit", all "Hieratic" monsters trigger a mandatory Trigger Effect when they are tributed (regardless if from the hand or field), to Special Summon 1 Dragon monster from the player's hand, Deck, or Graveyard, who will have 0 ATK/DEF
Where its at its best is on turn one helping you cast a ton of mana rocks, your Tymna, or a Rhystic Study, or slightly later, maybe on turn three, where it helps you double or triple spell some of your most impactful (but more expensive) cards