Given current content, having 3/3 with the right stats is more than enough. Anything else is just minmaxing for the sake of it.
Anything having a combination of KBW/Grudge/Adrenaline/Precise Dagger is your standard dps engraving. Master's Tenacity for berserkers, All-out attack for sorceresses, ambush master for back attackers, and hit master for dps that don't care about positioning.
Awakening/expert exclusively for supports, some niche stuff like stabilized/super charge for gunlancers.
That's pretty much it off the top of my head, may be missing one but that's the more desired. After that, you have the class engravings but since I only have one character I have no clue about that.