Make a personalised case for your mobile. Wool felt is the perfect choice: it's both stylish and protective. We have used Nepal Wool and needle felted a design. METHOD: Measure your mobile phone and add about 2 cm to both the width and length; cut out the front according to these measurements. The back should be the same width, but about 8 cm longer. The piece that sticks out will be the flap that folds over the opening. Needle felt your design with Nepal Wool. We gave the flap a terrazzo-inspired pattern and then sewed around the entire edge with embroidery yarn. Sew a button to the front and a piece of elastic to the flap to close it.