When you arrive you plonk all the clothes you have brought with you on the relevant table. (All the skirts on one table, all dresses on another table etc) Then help yourself to whatever you fancy. Simples!
At the end, we weed out anything which is a little small in size, keep a starter "seed" for the next swap, and send a box of donated stuff to a women's shelter. Can you imagine anything worse than being told you are too big for donated clothes when you have arrived at a shelter with nothing? I can't think of a worse punch in the stomach than that when you are starting again from scratch.
And here are the photos from today's swap. Some great stuff!