Like dodging, critical attacks occur only randomly and you have no real say in when you what to do one. However, like dodging, there is a weapon (The Bone Crusher) that increases critical attack chance and can be upgraded to increase chances. The Bone Crusher unlocks after earning 10 crystal stars, and should be fully upgraded to increase your chances of landing a critical attack.
pick up this weapon early on and keep it equipped and you'll have this achievement well before collecting all of the stars. You can check your progress under Stats – Combat.