Stephanie Kaloi of Offbeat Home & Life suggests applying henna with protective gloves because it stains skin. To apply henna, divide the hair into small sections, and then put a very thick layer of henna in each section. After applying the henna, wrap the head in plastic wrap and wait one to four hours before washing it out.
Kaloi notes that dyeing hair with henna is a large time commitment. The henna needs to be mixed and then sit for twelve hours for the dye to be released. After it is applied, there is another wait of one to four hours, depending on the desired shade of red. Henna can be applied to all hair types and to chemically dyed hair; however, it cannot easily be dyed over with another color or salon dye. Therefore, dyeing with henna is a commitment until the hair is grown out.
Kaloi also notes that henna does not look the same for every individual. How it turns out and the shade of red depend on the color of the hair before it is dyed. Henna also does not apply evenly everywhere on the head, leading to some hairs being lighter or darker than others.