Los Angeles, is the largest city of the southwestern U.S state of California.
Hitching in the Californian city of Los Angeles (LA) can be difficult, as in any major city wherein drivers are wary of shady individuals/drug addicts. One should make a decent attempt to look like a "non risky" person such as by smiling, or wearing bright clothing, or displaying alert or confident body language; this will lead to greater success in getting picked up. Stick to on-ramps, making sure to not proceed past the "no pedestrians" sign so as to avoid being hassled by the police. If you are a male and alone, you are likely to wait longer for a ride than you might elsewhere in California (Bay area excluded), but with patience you'll be picked up. Another factor to consider is the area of the city you are in; a middle class area or suburb might yield more success than hitchhiking out of inner city or upper crust areas.
LA is a notoriously sprawling metropolis, and if you are trying to hitchhike out of the city from anywhere other than the edge, you will almost certainly need to change cars at least once.
There are many on-ramps, and often you can easily walk from one to the next. It's good to ask locals about where you can find most traffic.
North on Highway 101
You may want to take the Metrolink train north to Oxnard and try hitchhiking along Highway 101 from there.
Take bus 534 from Santa Monica to Malibu,last stop,from there stick your thumb on a Chevron gas station,there is a friendly pocho guy working there,he met and fed many hitchhikers.Thumb may take you to Oxnard or even further to Ventura or Santa Barbara.It worked for me twice in a span of two years.
If you are in the heart of the City, or anywhere in Hollywood, West LA, etc., and want to go north on highway 1 / 101, I have developed a great strategy. You can take the Red Line train from Downtown Los Angeles to the Hollywood and Highland station. Get off there, and head south one major block to get to Sunset Blvd. Bus #2, which runs along Sunset, will take you all the way from Hollywood to the PCH (highway 1). Note: you don't have to take the red line to get there -- bus #2 runs along Sunset Blvd. all the way until the PCH, so just get to Sunset any way possible. At the PCH bus stop, you can transfer to bus #534 (as mentioned above), and ride that all the way to it's last stop in Malibu. You can essentially hitch hike straight out of the bus stop. I have hitch hiked out of Malibu, from that location, more than 10 times, and find it incredibly reliable, with minimal wait times -- and I generally score longer rides.
North on Interstate 15
Getting out of the LA area can be tricky. A spot with space and exposure is near the Ontario Mills Mall, where 4th street meets Interstate-15. From LA you can take the Red / San Bernardino Metro to the Rancho Cucamonga Metrolink. From there, you'll walk SOUTH (away from the mountains) to 4th street. Make a left on 4th street (going east). Stay on the left side of the street. In 2 large blocks, you'll go under the freeway. After that you'll see a stop light where traffic from Ontatio Mills turns left from 4th, onto the on-ramp. There's not enough room for a semi, but plenty of space for cars to stop.
South on 101 / 5 from Hollywood
West towards Phoenix
It'll take a while before you get out of metropolitan area. guaka was lucky to have a host all the way in Chino who picked him up at LAX and next day dropped him off another 30 miles or so west.
Personal experience--May 2015: I was hitching South on the 101, and was dropped off in Salinas. It took a full day to get out of there, although I spent many hours in the Pilot truck stop, on my laptop. But when I got to King City, I hitchhiked for a full two days, probably 6-10 hours per day, only to give up and use some money to take the Greyhound. Sadness. Here's hoping it changes out there in the central valley.
There's a latin-style church right across from Union Station. When Zenit walked past it, a dozen or so homeless people were sleeping right outside it - find it and you can probably crash there, too.