My first session this morning and I have continued to work all over the painting.  I continuously focus on shapes with negative space and contrast/light and shade.  Whilst I want the finished result to be vibrant I have to fight against mixing white in with my colours as I know that this will immediately have a flattenimg effect and a dulling of those bright colours that I want to achieve.  The advantage of using acrylic is that if I am not entirely happy I can fix more easily than with watercolour.