Henna is the byproduct of the henna plant and, when processed, it creates a dark brown or orange dye used to stain skin and dye hair. Whether you are making henna paste for your hair or for your skin, getting the right consistency is an essential part of the process. Well-mixed henna paste should have a consistency a little thicker than toothpaste. If your henna paste is too watery or runny, adjust the mixture at once.
Mix your henna paste thoroughly using a wooden spoon. This breaks up any clumps of dry paste, helping to thicken the henna.
Measure out 5 ml (1 tsp) of henna powder and add it to the henna paste.
Stir the henna powder into the paste, mixing thoroughly with a wooden spoon.
Check the consistency.
Repeat the process if necessary, adding the same quantity of henna each time and mixing until the paste is thick and no longer watery.
If you are applying henna to your skin through a bag, a slightly watery texture makes application a little easier. To work with watery henna, do two applications of the design -- one on top the other.