I found this to be a helpful travelers article from Magellans.com.  I know some in my family who shall remain nameless need to read this!  Yeah, you know who you are!

On most of business trips, I’ve fine tuned my packing to one small roll-aboard for about 3 to 4 days, and a larger roll-aboard for 4 to 7 days.  Yes, it is possible!

Highlights on the discussion of your wardrobe:

How to Get the Most out of Your Travel Wardrobe
Plan for and pack clothes that meet the needs of your itinerary, are appropriate for the culture and climate of your destination, and allow the most outfits from the least number of pieces. Here are some easy ways to lighten your load.

• Plan around a basic color. 
• Plan to wear each item several times during the trip.
• Take more tops than bottoms. 
• Choose lightweight knits, microfibers, cotton and silk over bulky sweaters, heavy denim and corduroy.
• Wear your jacket or coat and heavier shoes to the airport (worn clothing is never weighed).
• Pack for comfort.

Learn it, live it!

Seven Days and One Carry-on Bag | Magellan’s Travel Supplies