Read the directions on the box of your semi-permanent dye before even pulling out the goodies from inside and getting started. The instructions vary from one brand -- and even one color -- to the next, so study up before jumping in.
Put on a pair of plastic or latex gloves (some dye kits include them) and prepare the dye, following the instructions provided. Most standard at-home hair dye kits come with a basic applicator bottle. The dye goes in the end, pop on the top, and you're ready to go. No turning back now!
Separate your hair into four even sections, two on top and two toward the back, forming sort of square shapes of hair on your head. This method works well for all hair types, but especially on African-American hair, which tends to be quite thick. This is a method professionals use to ensure all the hair gets covered with no dry spots left over. Keep each section apart from the others by pinning each with a hair clip.
Apply the dye onto one section by squeezing the goopy stuff onto your hair from the nozzle of the applicator bottle. Rub the dye into your hair with your fingers until all the hair is covered in dye.
Clip the now-colored section back out of the way, and dye another section in the same way. Do this for the last two sections of hair, too.
Unclip all the sections and smooth over your hair with your hands, pulling it all together and giving it one more run through just to be extra sure there aren't any dry strands left.
Let the dye sit on your hair for as long as the instructions recommend for your hair type. Once the dye has processed on your hair, rinse your hair under cool water. Hot water is incredibly drying on hair, leaving you with more frizz and flyaways than shine and luster. Keep rinsing until the water runs clear, and voila, you're all done.
Your semi-permanent color should last through 12 shampoos -- or about three months if you wash hair once per week as recommended for African-American hair.
If you want a permanent dye job, speak to a professional first, or at least prepare your hair by using a deep-conditioning treatment on it once per week for two to three weeks leading up to dye day.
If you prefer, you can purchase a hair coloring bowl and brush -- or any basic plastic bowl and brush -- to hold and apply the dye.