Deciding how to pack light for a week, or how to pack light for two weeks, can be a challenge. In our day to day lives, we our used to having a lot of stuff available to us. Many of us have clothes that we haven't worn in over a year, for example. Trying to make a list of how to learn to travel light is relatively pointless, however, as it is based on your personal preference and experience. The best thing to do is that each time you go on a trip, whether it be a backpacking trip in the wilderness or a trip to another country where you are staying in hostels, is to make note of things that you do not end up using, or that you feel you could do without.
The biggest benefit of traveling light is that you can move faster and see more. Moving faster can vary based on the type of travel. If you are backpacking in the wilderness, you can literally move faster just by having less to carry on your back. If you are staying in a hostel, you can pack up your belongings much quicker when you are getting ready to leave for the day.