Final answer:
In a double-process technique, after rinsing the lightener and checking for scalp abrasions, you should apply the second process, which is usually a toner or color, to the hair. Rinse thoroughly and proceed with aftercare or styling.
Step-by-step explanation:
In a double-process technique, after rinsing the lightener and checking for scalp abrasions, you should follow certain steps to ensure the best results. First, you should apply the second process, which is usually a toner or color, to the hair. This step helps to neutralize any unwanted tones and create the desired color. After applying the toner or color, you need to let it process according to the manufacturer's instructions. Once the processing time is complete, you can rinse the hair thoroughly and proceed with any necessary aftercare or styling.