One of the tactical methods is space clearance.  According to the book of IM Paul Littlewood,  ” Chess tactics”  it appears, when:

“Square or diagonal needs to be cleared of your own or opponent’s pieces, before a winning combination can occur on that square or diagonal.” You should imagine the position without the obstructing piece on the way.

I played a blitz game today and got a little example of it,  Black to move:


The answer ( if necessary) is in the comment.