When performing a head tilt chin lift once you have placed your fingers under the chin what should you do next?

Once you've placed your fingers under the chin during a head tilt-chin lift, gently tilt the head back by pushing down on the forehead with your other hand. This action helps open the airway by lifting the chin and elevating the tongue away from the back of the throat. Ensure to maintain this position while assessing for breathing and preparing for further action if necessary.