Look for a pattern; look for enemy pieces arranged on the same line. Black’s king, rook, and bishop are spread along the back rank. If the rook were out of the way there would be a classic setup for a double attack with White’s rook: a king and loose bishop on the same rank with nothing between them. Can the Black rook be attacked? No. Can White attack something the rook protects? What does it protect? The knight on e4. So White takes the knight with NxN, Black responds with RxN, and now with the Black rook out of the way White plays Rd8+ and wins the bishop. That would be one way to see the position; another would be to begin by experimenting with captures. White sees that he can play NxN. Automatically he imagines it and considers what it would do to the board. It would cause Black to play RxN. Then what would be possible—especially what checks? Answer: the fork Rd8+.