How can you effectively curve a cue ball in billiards?

To effectively curve a cue ball in billiards, you can use English, which is a technique where you hit the cue ball off-center to make it spin. This spin will cause the cue ball to curve or change direction after hitting another ball. The amount of spin and the angle of contact with the cue ball will determine the curve. Practice and experimentation are key to mastering this skill.