Here, I'm blocking in the skirt form. I'm also leveraging a few contour lines - both around the skirt as well as a center line passing down the length of the whole body (from head, to thorax, to abdomen) to help establish how these masses align to one another.
This can be tricky at first, and requires you to really think about how your line runs over the surface of these forms, so don't rush through it. Give yourself the time to think carefully about how those surfaces turn through space.
Additionally, you'll notice some of the extra forms I've added to the head. At first glance, you may feel that the eyes - or at least the beady black things I assume are eyes - attach directly to the cranial mass, but if you look more closely you'll see that there's something of a supporting mass between them. I've drawn this in as a separate ball, even though it's quite subtle.