This Harry Potter Mask is fun for older kids to make, and can be adapted for other wizards or, of course, any other character too. You will need sturdy card to support it.
First, cut the shape of the mask out of sturdy cardboard - a pale flesh pink is ideal. The top of the head should extend upwards in a steep triangle, to support the hat.
Add features, taking inspiration from the photo below. To make Harry's glasses, form circles using pipe cleaners or soft wire, and wrap tightly with ribbon. Cut out the eye holes and then outline the eyes with pen or, as in the photo, stick seed beads around the edges. Draw on the eye details and eye lashes with black pen, or carefully stick on lengths of dark brown or black yarn. Add a triangle or red card for the nose, and draw on the mouth. You might want to draw around the edge of the mask with black pen to give it definition.
Add hair as appropriate for your character. Harry's is made using lengths of thin brown yarn. Glue to the mask and then, for added security, cover the join with sticky tape when the glue is dry.
You can approach the hat in two ways. First, make a 2-dimensional hat by cutting a triangular shape out of fabric or felt and gluing to the top of the mask. Decorate, and add a pompom at the top if you like. Second, make a 3-dimensional hat by attaching a "real" conical hat to the front of the mask in such a way that the child can wear the hat properly with the mask on.