Exchanging clothes have proven to work very well as the fast fashion trends produce much more clothes than one could possibly wear.
First, you need to find a location and a timeframe for your swap shop. This can be anything from a day event in a park or on a square, to a regular event in a gallery, project space, or social center. The good thing about making a regular event is that you will gain closer ties with your surrounding community but it needs more organization and a place to store the clothes you will have left over. Once you have your space and time, think of what you will need to present the clothes well, and how many people you will need to be there. It is nice to have the possibility to re-make and repair old or broken clothes at the spot, so do consider organizing sewing machines, scissors and people who are willing to teach others about different techniques. Then promote the event wherever you can. Make sure it is clear how you plan to exchange. You can make 1 to 1 exchange, ask people to bring food if they do not have clothes or make it totally open to bring and take what you want. Plan some time, like an hour, to set up the swap shop with the clothes you have gathered with your team on beforehand. When people come to exchange, ask them kindly to help sort their own clothes onto the hangers or the washing line. Often people come with big bags of clothes. Enjoy and take time to speak to people.