One of my wife and my favorite things to do is go to this place in the Inner Richmond called Green Apple Books. We're both bibliophiles, so we'll go there and spend a lot of time.
There's a great dim sum place nearby called Good Luck Dim Sum. Good Luck is the kind of place where two people can spend $15, and you're incredibly full, and then you still have a thing of leftovers. You can pick it up and take it to the park and eat it there. If you're not into dim sum, there's a place called Bunn Mi that I think is the best banh mi in the city.
One of our other favorite places is a place in the Mission called Wise Sons Deli. You can't go wrong with the Reuben there. They make their own pastrami, and it's the best I've ever had.
If we're in the Mission, we'd walk up and down Mission and Valencia, and just window shop. On Valencia, you can't go wrong with Ritual. That's quality coffee. Borderlands Books is an amazing place for sci-fi, fantasy type books. Paxton Gate has great quirky nature stuff and jewelry. It's really interesting and a fun place to browse. They have some weird taxidermy.
Right next to Paxton Gate, there's a pirate store. I think the deal is they wanted to open a tutoring center and couldn't get it zoned, so they opened up a pirate store. There's tutoring in the back.
So, the Inner Richmond. The Inner Richmond is like, the real Chinatown, and I'd start there.
If it's a naughty day, I'd go to one of the fast food-y dim sum places: Good Luck Dim Sum. It's the kind of place where if you take too long, you get yelled at by the ladies, and there are like seven wobbly tables. The soy sauces comes out of ketchup bottles. It is low key. I'd be there to get the sticky rice with chicken, in lotus, which is like $2. You can have that and a cup of porridge, and it's super good and super hearty.
There's a really good bookstore down the street, Green Apple Books--both new and used. There's an annex to that, which also has periodicals. They've opened up another store that's next to Golden Gate Park.
I always see people in Golden Gate Park and they're just on their phones. You know, it's like, don't sit on your phone and be in the park. Walk to Green Apple, and buy yourself a book and read it in the park. It's one of those places where they're always playing weird music, like Japanese death metal or something. I am a huge fan of all the cultural institutions in Golden Gate. The De Young is great, so if you have a friend with a membership, go with them.
After that... I don't go that often, but there are farmer's markets everywhere. Everywhere. Like, there's one in front of the Kaiser Permanente. If you don't have a chance to get out of the city around San Francisco, go to one of the farmer's markets. It's a good representation of why California people are so spoiled when it comes to food.