What makes this different from a generic swap is the curation that comes with a community-specific event — sizes, styles, and general aesthetic tend to cluster in ways that make the browsing faster and more useful. Lake Merritt is BART-accessible (Lake Merritt station, about a 10-minute walk depending on where around the lake they set up), and the park itself has plenty of flat grass for blankets. Bring a bag you don't mind carrying the swap haul home in, and bring more than you think you'll give away — the ratio of givers to takers matters.

If you've got two hours: drop your donation bag first thing, do a full loop of the swap tables while others are still laying out, then grab a spot on the grass before the picnic crowd thickens. The early arrivals get the best selection.