Figure[White to move]

Are any Black pieces loose? Yes, the knight at d7. Can White’s queen attack it and deliver check at the same time? No, but Qg4 would aim the queen at both a loose piece and the king; it would be a winning fork but for the pawn at g7. White’s goal therefore is to draw that pawn out of the way. Ask whether the pawn is protecting anything that White can attack, and you are led to 1. Bxh6; now if 1. ...g7xB, then 2. Qg4+ takes the knight, gaining a pawn and wrecking the Black king’s pawn cover.

These first three examples all are basically the same, of course; they involve creating holes in the king’s pawn cover so that the queen can check the king and attack a loose piece elsewhere at the same time.