2 Wear comfortable shoes. Most of the time you will walk a lot.
3 Buy rechargeable Clipper Card or a multi day Mini pass at any Walgreens or partner retailer to easily ride cable cars, street cars, buses and BART. It will save you time and money, because drivers have no changes most of the time.
4 Be prepaid if you rent a car: its common to look for parking slot for 15-30 min
5 15% tips is standard in the restaurants. Bellhops and porters should get 1-2$ per bag.
6 For 40$, a CityPass admits you to the San Francisco Museum of Modern Art, the Asian Art Museum, the Exploratorium, and either the California Palace of the Legion of Honor or the California Academy of Science and includes bay cruise as well as seven days of transport on the San Francisco Municipal Railway System. If you purchase everything separately you will spend twice more. You can purchase it on www.citypass.com
7 Avoid Civic Center and the Tenderloin area (near Union Square) after the dark. A lot of homeless people there and dirty
8 Try to make reservations before going to restaurants (especially during dinner time) to get a table and buy all museum tickets online to avoid crowds.
Have a good day and best travels!