Everything is practice.
1. Download a chart to help you diagnose as to why you're drifting off target.
2. Learn how to properly grip the gun in a way that maximizes accuracy and feels natural to you (there are several good accepted grips).
4. Make it second nature to look down the sights, before, during, and after the trigger pull.
5. Did I mention practice? Few people are naturals, most good shots have a lifetime membership at the range and operate from muscle memory.
6. Stay safe.