So, let me give you an example of what I meant, using a character I've written up but not played. He wants to turn himself into a were-dragon, enchanting a necklace to give him the power to transform. Mechanically, this is Item of Power [+2], Beast Form [-1], Echoes of the Beast [-1], and Human Form [+1] affecting Wings [-1] and Claws [-1], for a total Refresh cost of [-1]. He's already got Unseelie Magic to use for the breath weapon, and Inhuman Strength/Toughness, so he doesn't include either of those in the ritual.
So, setting up the ritual, he Invokes his High Concept (Nerdy Winter Knight) for the raw power to power the ritual, and his Trouble (Mantle of a Monster) to give him the predatory instincts to use his new form properly. He then uses his Scholarship to make three Declarations: I Have A Degree In Aviation Technology, to work out how to get the thing flying properly; The Mind Of An Engineer, to reflect his past training with mechanical engineering to work out back-of-the-envelope calculations on how the basic mechanics of how its limbs and whatnot would work; and I've Read A Lot Of Wikipedia, for the biological knowledge to make sure it wouldn't just keel over and die on him.
This is a total of five Aspects invoked/tagged, for a total of five Fate Point-equivalents; so the enchantment on the necklace would last for five scenes or the next noon, whichever came first, right?