Cut one foot from an old pair of nylon stockings and stretch it over the opening of a tall plastic container. Tuck the nylon toe down into the container and pour your henna powder into the toe. Gently shake and tap the container until most of the henna is through. Store henna stuck in the nylon for later projects.
Dissolve 2 tbsp. of sugar into a cup of lemon juice. Pour your sifted henna powder into a ceramic bowl and add your lemon juice and sugar, stirring with a metal spoon, until you get a thick paste the consistency of pudding.
Cover the bowl tightly with plastic wrap and set it in a warm place overnight so the henna can release its dyes. The lemon juice will help concentrate the color and push more dye into your skin, while the sugar will help the henna paste to stick to your skin longer.
Clean and dry the area to be tattooed thoroughly with soap and water. Choose a place with thick skin and little hair, such as the hands, back, shoulders or soles of the feet. Your work space should be warm; warm skin absorbs more dye.
Load the henna paste into an applicator bottle with a spoon. These are thin plastic bottles with thin, tapered cones on the lid. Fill the bottle all the way and squeeze it to make a thin line of henna on the skin.
Seal the henna tattoo with a cotton swab and hair gel when the paste feels dry to the touch. Gently rub a thick coating of hair gel over the tattooed area with a cotton swab. Do not shower or get the area wet while the dye sets. Let it set for eight to 12 hours.
Wipe away the gel and henna paste gently with a soft dry towel. The henna will look light; it will cure and darken for a few hours after removal. Pat the tattoo dry and avoid spraying it directly with water after it cures fully.