Practice practice practice. Go to the training ground and work on it. Start by aiming at the center of the goal. Once you’re comfortable with that, then aim for either left or right half of the goal. Don’t try to aim too small and go for corners right away. You’ll have some error in your aiming caused by other you or the way the game works(extra touches from your player, input delay, etc.). So by aiming at the central part of a bigger portion of the goal, you’ll hit the target more often. But practice is the single biggest thing that will help. Good luck!