That’s one of those chess rules of thumb that everyone should know: When ahead, trade pieces. When behind, trade pawns.
That actually just came up for me in a game last Friday. I got ahead by 2 pawns against a lower rated kid, but he made it tough for me to go after his king or win anything else. So I just wanted to trade the rest of the pieces and let my extra pawns win the endgame. Much to my delight, he offered a queen trade, then several other pieces trades. The only trade he didn’t want was the final pair of rooks. Apparently, he knows the old saying, “All rook endgames are drawn”. Lucky for me, that’s an exaggeration, so I got the full point.
In one multiple-time-control game I had a near-even game, a 150-point rating edge and a noticeable time advantage. I used my extra time and complicated the position to the max, ending up with a combined seven vulnerable pieces. My opponent made the time control but made a few second-best moves that gave me a positional edge that I used to win the game.
In another game (high school 8-board match) I was getting squeezed to death in a materially equal position (40/60 for the first time control). I was in severe time pressure, my opponent knew it, and he continued the squeeze. Finally he noticed that he was also in severe time pressure and whipped off four moves. I responded as quickly as I could and those four moves reversed the positional edge. I made time control with about four seconds to spare (four seconds into move 41 he called the flag, at which point we saw that he had missed two moves and thought it was only move 39). The match was tied after the other seven boards were done and my eventual win gave us the match.
The third one is funny, the first one would likely be regarded as illegal by many TDs (it amounts to referring to written notes during the game), and the second belongs in the Worst Sportsmanship thread.
Number 2 brings back memories. Many years ago, I was in desperate time pressure vs. a high-school age player. He blitzed off a move setting up a transparent cheapo and, as he withdrew his hand from the board, pointed at the piece he wanted me to move - so quickly that the gesture was almost invisible. This “subliminal” gambit had the desired result, as I immediately moved the indicated piece, losing my queen.