Wrap your belt along the inside edge of the suitcase. This will keep your belt from creasing and will help hold other clothing in place.
Fold your pants in half at the midline seam. Fold them again lengthwise in half or in thirds so they fit the full width of your bag. Lay them on the bottom of your bag.
Turn your suit jacket inside out and fold it in quarters: Fold it in half along the center of the back and in half again at the waist. Lay the jacket on top of the pants.
Fold your dress shirt into thirds lengthwise by folding the shoulders toward the back. Fold the top of the shirt, but roll the tail of the shirt, where wrinkles will be hidden because the shirt tail will tuck into your pants.
Roll up your tie and store it inside one of your shoes. (ref 2) Pack your shoes at the wheel end of the bag so they won't crush other clothes. (Ref 1)
Unpack your suit as soon as possible after you arrive at your destination.
