We have done this activity in a few wards I have been in, and it has been a success. It can be as big or as small as you make it.
Invite members of the ward to donate things they no longer want or need – any “surplus” items. Items are then organized by the youth (Our YW did this) on various tables by type. (Clothing table, canned goods table, arts an crafts table, shoes table, books, jewelry, etc.). People were asked not to bring things ready for the trash. These items were to be gently used – no rips, no tears, etc.
This was done on a saturday from 9a-12n. The youth spent the previous Wednesday organizing and sorting all of the things that came in. Fliers about the market were distributed all over the neighborhood, even to nonmember homes. They were invited to bring their own recycled shopping bags to carry their things. No money was involved. This was a take-what-you-can-use type event.
The bishopric handed out hot dogs and cookies.
Afterwards, several trucks were filled with what was left and hauled off to charity.
It was great! People had some really good finds, and no one felt as if they were getting a hand-out, because we were all just sharing. And it was a good support to the youth.
This event could also be tackled by a YW for a Personal Progress Value Project, of course with the help of others.