After completing your swing, swipe towards the side you want the ball to travel while it is in the air. The distance the ball travels depends on the speed of your swipe as well as the strength used during the swing. Aim is the most important stat of your character and should be upgraded whenever possible.
Resume playing quickly
After expending all your golf balls, instead of waiting the usual amount of time for them to regenerate, advance the time on your device. After getting your golf balls restored, set the time back it its correct value.