Deal with the bottom enamel in the same way. Retain introducing flesh tone to your lips until eventually you’re content with the value and power. Make use of a darker purple combination (French Ultramarine and Alizarin Crimson to the blue aspect) for your darker crevices in between the enamel. Also https://trendycatportraits.co.uk/personalised-watercolour-painting-from-a-photo/