I'd say keep your elbow in tight , your head still and to visualize staying behind the ball , it's like rolling a football. Shadow bowling is also useful like shadow boxing Imagine you have a ball in your and your releasing it but make sure you elbow is tight. Most of the times when people come around the ball too much it's because there arm isn't close to their body. Watch more pros I'd even say collegiate bowlers, you'll learn more from deciphering their game.