I love blocking wool felt. It is easy to work with and I especially enjoy making free-form shapes. For this I use a plain wooden head block and form pleats and tucks in the wool felt. I let it dry to shape and then I usually go back and stitch the shapes I have made so they hold. All my wool felt hats are lined with a soft cotton twill and a Petersham ribbon band.  The hats pictured are two of my favorites!