If you're in SF April 29 - May 1st, without a doubt go check out the Spring Renegade Craft Fair. Held at Fort Mason there are so many good vendors, makers, foodies + crafters you will never be disappointed. Although I can't make it this year, go for me + have some drinks + take some pics : ) Be aware that April 29th is a wholesaler only day, April 30 - May 1st is open to the public.
Cost: FREE