You will face fewer lines at the airport both at check-in, when you just sail right past passengers waiting in those annoying long lines to check their bags.
No matter how long the trip, don’t pack more than one week’s worth of clothes. Plan to do laundry along the way for a longer trip.
Plan color-coordinated outfits. If something doesn’t work in many different outfits, leave it at home. Nothing can have a one time, one purpose use.
Don't pack bulky things when flying. Wear them on the airplane. Think, winter coats, heavy sweaters, really clunky shoes or boots.
Rolling your clothes instead of folding them in your suitcase minimizes wrinkles and maximizes space.
The advantages of packing not only lightly, but smartly, are huge.