Start with clean, dry hair and part your hair as you normally would. You’ll want to use the product on dry hair, since wet hair can dilute the product you are using.
Mix your at-home highlighting kit. The lightening product will be mixed with an activator of some sort.
Apply your highlights working from front to back; be sure you apply the color from root to tip in one swoop on small strands of hair. Also, make sure that you space your highlights out evenly from one side of your part to the other. If you are touching up old highlights, only highlight the regrowth instead of painting the whole strand, which can cause unnecessary damage.
Allow hair to process according to the directions on the package, anywhere from 20 to 45 minutes, then rinse, shampoo and condition your hair.