In Create an Advantage, there is a difference whether a character is creating a whole new Advantage that didn't exist before, or if they are using a pre-existing Advantage (which was always there in the situation or location, but the player wants to make it important to the story). For a New Aspect, a Tie result will only create a boost (temporary advantage, one-use). You need a Success (at least 1 Shift on the roll) to create it with one free invocation (invoke). But for an existing Aspect, if you either Tie or Succeed, you get one free invoke. In each case, Success with Style (3 Shifts or more) gives you TWO free invokes.