Kirby's shot prediction shows you exactly how the current shot will go if you hit it perfectly. Ideally, you want to use this on shorter approach shots where it's easier to fine-tune the process. You don't have to hit the exact shot; if shot prediction shows that you weren't close enough and you adjust, it still counts.
If you're having trouble, grind it out by playing rounds of City Park's par 3s at Amateur difficulty. Intentionally drive short so that you're still on the fairway, then shoot a pitch shot with max backspin to get as close as you can. This also adds a point towards another achievement.
The In a Spin achievement in Powerstar Golf worth 19 pointsPlay ten shots using backspin, stopping within 5 feet of the pin.
If you add sidespin, you'll also get a point towards another achievement.
The Curveballs achievement in Powerstar Golf worth 23 pointsPlay ten draw or fade shots, stopping within 10 feet of the pin.