Use Trim Screws or Counter-Sunk Nails from Above

Locate the floor joists beneath the creaking boards (use a stud finder or tap gently). Drill small pilot holes through the floorboard and subfloor into the joist. Drive trim-head screws or finishing nails into the pilot holes, countersinking the heads slightly below the surface. Fill the small holes with wood putty that matches the floor color. This secures the board directly to the joist.