Any tips on painting like jenny saville?

Im doing a project on portraits and with each artist i research im producing a painting in the same style. For jenny saville i took a photo of my face pushed against a pane of gl, like in one of her painting, any tips on how to paint like her? im going to use oil paints. ( this isnt my first time using oil paints, ive also done a painting similar to lucian frued and a couple of others)