To perform a perfect dodge, you just need to simply dodge into an enemies attack, taking no damage.
It's a lot simpler than it seems. You dodge into nothing, it's a regular dodge. You dodge into an enemies attack, taking no damage because of it, this is a perfect dodge.
Let's say you're fighting a Shrike. When they launch the tornado at you, you dodge INTO the tornado as it's about to hit you, so that your invincibility frames kick in and you dodge through the attack itself, taking no damage. That's 1 perfect dodge right there.
There's no in-game tracker as of yet, so you just gotta keep going at it until it pops.