[I use two boxes of the Henna and the Indigo because I have pretty thick hair and would rather have more than enough product to cover my hair liberally].

The Process: 

You will first need to apply the Henna application. The quickest, easiest, and fuss-free way to do this would be to just apply water to your henna mixture until it reaches a thick, muddy consistency.  

1. Add henna powder to a plastic bowl
2. Slowly pour in distilled water while stirring
3. Once the mixture has gotten to a thick, muddy, consistency, cover and store in a cool place for about 24 hours.
4. Apply mixture liberally to your hair, cover and allow to sit for about 2-3 hours. – Do not manipulate your hair too much over this time. Manipulating it can cause a mass of tangles and knots.
5. After 2-3 hours, rinse with water until you rinsed out most of the Henna. You can then rinse the remainder of the henna out with the aid of conditioner, OR you can immerse your hair in a tub filled with water. Either the above methods are effective in removing the tiny flecks of Henna.
6. Once you have thoroughly rinsed out the Henna, it’s time to mix your Indigo.
7. In a new clean bowl, add Indigo to your bowl
8. Slowly pour in distilled water while stirring
9. Once the mixture has gotten to a thick, muddy, consistency; you can apply it to your hair! No need to wait, this stuff releases color immediately.
10. Apply it the same way you applied the Henna. Make sure you apply this mixture from the roots to the tip for nice, even coverage.
11. Allow the Indigo to sit for about 1-2 hours for a rich, black tone. For even darker tones [like jet black], leave it on overnight.
12. Rinse with water until you rinsed out most of the Indigo. You can then rinse the remainder of the Indigo out with the aid of conditioner, OR you can immerse your hair in a tub filled with water. Either the above methods are effective in removing the tiny flecks of Indigo.
13. Now it’s time to condition your hair. Deep condition [with heat] using your favorite deep conditioner. This restores healthy moisture levels in your strands, making your hair flexible, and full of body.