If you’re one who travels and don’t own garment bags to carry your suits in, here’s a proper way of folding your jacket when packing in a suit case:
-Empty pockets and unbutton the jacket.
-Hold the jacket facing you and place hands inside jacket’s shoulders.
-Turn the Left shoulder inside out (but not the sleeve).
-Place the Right shoulder inside the left shoulder. The lining is facing out and the sleeves are positioned inside the fold.
-Fold the jacket in half and place inside a plastic bag.
-Pack the jacket.
Courtesy of: http://www.noblehouse.us