The product is a powder, so you mix only the amount you need immediately before application. This makes the texture adjustable and keeps the remaining powder from absorbing moisture from a prepared batch. Put a small amount into a clean, non-metal mixing dish and add lukewarm water or the mixing liquid specified in the product instructions, drop by drop. Stir until you get a smooth paste with the thickness of toothpaste — it should be spreadable but not runny. If it is too thin, the dye can creep toward the lash line; if too thick, it sits lumpy and applies unevenly.
Before mixing, make sure the brow area is clean and dry and free from oils, creams, or makeup. Using a clean angled brush or cotton bud, outline the underside of the brow first, then fill the body of the brow in short strokes. Work quickly but carefully: henna-based brow dyes usually stain the skin as well as the hair, and the edge you create will be visible for a few days. Wipe away any paste that lands outside your intended shape straight away with a damp cotton bud, before it dries.
Apply a thin, even layer only to the brow hair and the skin just below it. Avoid getting the paste into the eye, onto the eyelid, or between the lashes. Leave it for the recommended development time, then remove with a damp cotton pad or rinse with lukewarm water. After removal, keep the area dry and do not rub it or apply strong exfoliating products to the brows for a day or two while the tint settles. Seal the remaining powder tightly after use and store it in a cool, dry place away from moisture.