Sacrifice to Block the Path
Interference almost always involves a sacrifice. You must be willing to give up one of your pieces by placing it on a square where it will be captured, just to achieve the goal of breaking the enemy's defensive coordination.
Identify the Defensive Line
The first step is to trace the lines of defense. Which piece is defending which other piece? Once you see that line, the idea of blocking it becomes much more intuitive. Look for rooks defending each other on a rank, or a bishop and queen working together.
A Move That Made History: The "Immortal" Zugzwang Game, Saemisch vs. Nimzowitsch, 1923
In this legendary game, Nimzowitsch puts on a masterclass of positional chess, culminating in a state of complete paralysis (zugzwang) for his opponent. A key theme throughout the game is interference. Nimzowitsch places his pieces not to attack directly, but to block his opponent's pieces from moving to key squares, completely disrupting their coordination. The final position is famous because Saemisch, despite not being in check, had no legal moves that didn't result in immediate material loss and was forced to resign.
The Winning Combination: This entire game is a lesson in positional interference.