This is an extremely simple mental tip -- well, simple to say but maybe not so simple to do. This Martin Hall clip aired on Morning Drive the week Russell Knox was defending at the WGC in China. It's a driving tip Russell got from Lynn Marriott at VISION54.
Mental tips like this, despite their simplicity, can be unimaginably difficult to use under pressure. That's why you need to spend a little time practicing them on the range before you try them during a round.
Why is this "imagine you're driving your ball into the ocean" swing thought so difficult? It's because your actual drive MEANS SOMETHING TO YOU. You can do the practice swing where you aren't actually hitting a ball just fine but, once you set your driver behind that teed-up ball, your mind simply says, "HEY, BUDDY. THIS TIME IT'S FOR REAL." And if you've been having trouble hitting the fairway anyway, that's all it takes to tighten you up.
And once you tighten up, there's a good chance you'll miss the fairway again.
It may help you to remember what Martin says in the video -- namely, that you won't hit every ball perfectly by doing this. However, your overall percentage of fairways hit will go up. This is an "improvement" drill, not a "do it perfectly" drill.
And this is one place where all my recent posts on learning to square the clubface by using your arms and hands more will help you. The ball goes where the clubface is aimed at impact. If you focus on squaring your clubface instead of steering the ball, that's where the ball will go. It may curve a bit if your swing path is off, but it will still curve toward the spot where your clubface is aimed.
Where the ball lands is what matters. This tip should help you land it where you want it to land, and land there more often.