I constantly read about hipsters, but I don't actually see many while walking down the street. I suspect that hipster styles and Los Angeles's climate just don't go together.
The basic idea is to look like President McKinley wasn't assassinated and the whole 20th Century thing never happened. Back in the old days, people wore a lot of layers of wool because everybody lived in England or Cleveland or someplace and the coal for your stove wasn't free. To the eye of a Californian with central heating, everybody in sepia-toned photos looks awfully sweaty under all those clothes.
California was central to a major post-1960s revolution in how men dressed, as guys started to wear clothes light enough for the climate (e.g., the Silicon Valley casual look), even at the expense of giving up all those potentially fashionable coats and hats.
So, Southern California is just too warm most of the time for ironic old fashions best suited for Portland. Every so often on a cool winter's day here, I see somebody wearing some Portland-style hipster garb, but then the sun comes back out and it gets uncomfy for them.
A few years ago, my nonagenarian grandfather drove himself to Urban Outfitters and bought one of his grandsons a present of a wool cap, the kind of tweed thingie that Bobbie Jones' caddie at St. Andrews probably wore. When unwrapping the package, my son pretended to be enthusiastic about wearing his grandfather's fashion choice, until he saw it, and decided it was cool. He wore it everyday (and I started seeing pictures in the press of Brad Pitt wearing an identical one). But then February arrived and it got too warm for hipster clothes.