First you need to put your jacket on the flat surface like a table and brush it to remove the dust
, dirt, loose leather stripes. Then massage the jacket with saddle soap, and then let the jacket dry naturally. Apply leather repairing compound to the damaged parts only. Use leather glue on the crack to join it and put some weight on it. Let the leather glue dry by itself. Remove the scrap material. Use sand paper to remove any extra glue left on the cracks outside. Apply the leather conditioners and keep on applying that once a week. By this your men's leather jackets will remain soft and flexible due to which there will be no more cracks formulation in future.