Regularly change the water you rinse your brushes in and work preferably with two water dishes: one for light and one for dark shades.
When working with Water Make-up preferably use separate brushes for light and dark colours.
To make beautiful, thin lines easier, mix the Water Make-up with Cleansing Lotion instead of water.
Water Make-up can be used to add (additional) colour to the hair and eyebrows, provided that the hair is not permed, bleached or dyed. Use a toothbrush to do this.