If you are longer off the tee than your opponent, stand next to your ball as you watch him hit his second/approach shot (as long as you aren’t near his line of play!).
Your opponent will feel pressure to deliver a decent shot as you loom rather menacingly in the foreground.
If you are playing first your objective should be to put pressure on your opponent.
Hitting the centre of the green or laying up in the ideal spot on a long par 5 will place extra stress on him as he contemplates his next stroke.