How can I properly countersink a screw to ensure a flush and secure finish?

To properly countersink a screw for a flush and secure finish, follow these steps:

1. Choose the right size drill bit for the screw head.
2. Drill a pilot hole for the screw.
3. Use a countersink bit to create a recess for the screw head.
4. Place the screw in the countersunk hole and tighten it securely.
5. Check that the screw head is flush with the surface for a professional finish.