Place your index fingers on either side of the client's head, just above the cheekbones, and run them back through the hair horizontally until they meet.
Clip the hair up above your fingers to create two sections, one consisting of roughly one third of the client's hair, on top of her head, and the other two thirds loose.
Pinch one of the hair extension strands between the thumb and index finger of one hand roughly half an inch from the top.
Apply hot glue to the top of the strand with the glue applicator, using your other hand. Follow the manufacturer's instructions for heating and using the glue to avoid injury. Ensure that all the individual hairs in the strand have been coated with the glue at the top, then put the glue applicator safely to one side.
Section off a small area of hair from the left side of the free hair, near the parting. Lift the section away from the rest of the hair with the point of the rat-tail comb. Hold it with your free hand. It should be roughly the same size as the extension strand.
Apply the glued end of the extension to the strand of hair an inch from the roots.
Hold both strands of hair together near the glue with one hand. Use your thumb and forefingers from the other to roll the glue around the natural hair and hair extensions and bond them together. Ensure the glue forms a complete seal around both strands of hair.Repeat the process. Apply the glue-in extensions at regular intervals along the free-hair section parting to achieve the desired effect.