It's pretty safe to assume that almost everyone here is aware of the two different kind of feints. But I don't see a post about it so I thought why not?
Feint Dodge type 1~
The easiest feint to preform. If you get hit, just dodge during your Stagger or Stun animation. This feint offers you a temporary state of immunity to on hit effects like Stagger and Stun, but it is also the more SP taxing one, and should only be used when it's more beneficial to use than the other one. Also I should mention the Invulnerability only lasts as long as you are in the dodge animation. The second you cancel it to run, or to attack you lose that invulnerability to on hit effects.
Feint Dodge type 2~
A bit trickier to preform. If you get hit you must press space to start a hit recovery animation, then dodge. This feint does NOT offer you a temporary of immunity to on hit effects. So timing this one properly is more crucial. Though the upside is that it takes the same amount of SP as a normal dodge, and is the better one to use in situations where you'll want more SP.