Choose colours: lemon yellow,  ultramarine blue, paynes grey (neutral tint)

whitelilac sketch   whitelilac1   whitelilac2

Roughly sketch the composition, lilac flowers are easy to draw - an irregular triangle. Draw 3 flowers different shapes, sizes and angles. Think about the spaces between where the leaves will go

  

 Spray the whole paper with clean water. Drop different green tones all over the paper. With kitchen paper dab out the edges of the flowers leaving green areas in the centre of the flowers

 

   Dry well - with white gouache define the flower shapes leaving some pale green tones in the centre, use irregular blobs. You can also use a white felt tip pen (it should be opaque ink)

 
whitelilac3    whitelilac final    
Add leaf shapes using different tones and placing part of the leaf under the flower. Add twigs and shadows under the flowers    Add a few more green tones in the flowers and the tiny yellow centres (lemon yellow is an opaque watercolour