In the 'downtown' area, of the N.E. Quarter of the City, i always try to park a block North of Union Square at the Sutter Street X Stockton Street Garage(called 'sutter stockton'). It seems to have the lowest daytime and overnight prices downtown. And instead of wasting time looking in the lower floors, i take the FAST double helix up to the top or upper floors and have NEVER NOT FOUND A SPACE... Be sure to not leave valuables in sight or in your car if you can help it, even tho this is a 'safe' part of SF. Overnight was recently as low as $9/night. Many garages downtown charge $20-30/day...
Parking tickets on the street are very expensive, like OVER $50, so i usually try for a cheap garage or big big lot with less chance of a hit and run or door dings. NEVER ARGUE WITH A SF COP(yikes!!) OR METER MAID. If you get your car towed from the street, you will be in a world of Hurt, as for instance the last city contractor was found guilty of towing legally parked cars and extorting $100s from unsuspecting tourists !!
Also , Beware, as some / most of the hotels have discovered a new profit stream of charging separately for parking, from $20/night to upwards of over $40/night with valet parking!!
If you come into the SF/ City from the South / Peninsula, ALWAYS USE HWY 280. Highway 101 is much more crowded and has more accidents and lots of terrible amateur drivers. Near the BALL PARK, you can park in big lots if you turn South on the 3rd or 4th Street Bridges, for about $6/day. There is good streetcar transportation or taxis just North by the BALL PARK or CALTRAINS STATION.
Another good area to find cheap day or night or long term parking is on the WATERFRONT called "the EMBARCADERO". There are many piers, starting with Pier 30 just South of the Bay Bridge, that let you park for $10-15/day. Going North, up the EMBARCADERO, with the water/Bay on your right side, you will see lots of parking lots beside the ODD NUMBERED PIERS, like Pier 17-21 area.
FISHERMAN'S WHARF has a validated garage by Walgreen's ,,, also near to SCOMA'S RESTAURANT on pier 47 / Castagnola's restaurant and the very famous skipper "Wacky Jacky's" boat.
On the North edge of the City, THE PRESIDIO use to have scads of free parking at Crissy Field (now mostly lawn and pond , unfortunately) or by the Parade Ground. But, Beware, the private for profit company that is running this federal land-former Army base is looking for ways to make fast bucks ,,, so don't expect free parking to last much longer in the PRESIDIO.
Stay away as much as you can from the S.E. Quarter of the City(on a map that would be all of the lower left 1/4 of the City), called "THIRD STREET", as it is very poor and very high crime.
As for the other 2 Quarters of the City, you many find some parking in the highly residential S.W. Quarter, but, Beware, as many home owners there 'thinkk' they own the curb in front of their houses on the public street. Same goes for the N.W. Quarter. Be informed that NYC and SF are the 2 most expensive cities in the "lower 48 states" and over 70% of SF residents rent or lease at Outrageous prices, so tempers around street parking are always short.
There is a RV LOT down in the S.E. Quarter (xxx) next to CANDLESTICK , or 'the stick', where the "49ers" football team sometimes plays. Be forewarned , that is a very very dangerous quarter of the City ,,, and very very polluted.
Be safe and Enjoy the Amazing City by the Bay (highly polluted) !!
