Perhaps you want to sample the local food. Get a real feel for what the locals eat.
Search out street fairs to purchase a locally made trip souvenir. Often these are less expensive than what you find in “tourist shops”.
Take a ride on the F Line Trolley car in San Francisco. When you get home, frame your ticket and a photo of you with the trolley car for an inexpensive memento.
Again, sample some local food at a farmer’s market. If you are thinking about an expensive restaurant, check our http://www.restaurant.com/ and buy a $25 gift certificate for only $10. Look at any day or time restrictions, but usually these are a great deal.
Cash in any hotel reward points quickly. Don’t save for a “foggy day”.