Before entering any taxiway or runway what must be done?

Before entering any taxiway or runway, a pilot must ensure they have received a clearance from air traffic control (ATC) if required. They should also perform a thorough visual check of the area to confirm it is clear of other aircraft and vehicles. Additionally, the pilot should verify their position on the airport diagram to avoid any inadvertent incursions. Finally, it's essential to communicate intentions clearly on the appropriate radio frequency.