Knight Sackrifice

Yeah, sacking a knight for 2 only in the endgame if the pawns are passed or bound to be passed
Or there are cases when you sack them for both pawns in front of the enemy king, in order to open the files. That kind of sac also MAY be good, but varies. It works better if your pieces are mostly on the enemy king side
In general, I wouldn't recommend, though...