Yeah, that's the thing. The Evocation-speed things that could fit are either giving yourself an aspect and then tagging it immediately, or using it as an attack, and make it as if you're using a skill with the power shifts going into success shifts. (So, a 4-shift Might boost like using a 4 shift attack)
But it doesn't LAST long, is the problem. The Windcrafting flight as shown in the books can be kept going for hours, if need be, for example, but called up instantly.
One of the things I've been thinking of, is maybe mashing up a bunch of rules. Like, say, you can have an X-Crafting effect that boosts a skill, but every round you do keep it up, you work it like the discipline rolls to cast a spell, only you don't automatically take a point of mental stress.
So, if you don't push yourself, you can reap the benefits for quite some time. But if you're going balls to the wall, you get drained fast.