In my particular case, I was dealing with fabrics I'm familiar with, size charts I can trust, and a tape measure I am comfortable applying to my own body. Combi

In my particular case, I was dealing with fabrics I'm familiar with, size charts I can trust, and a tape measure I am comfortable applying to my own body. Combined, these factors cut down greatly on the uncertainty. I realize that I don't represent the typical shopper. I can tell you from experience that SF specifically, and the Bay generally, has a pretty wide variety of clothing available from a series of retailers. I've seen everything from one-person brands to chains and lots of things in between. You sometimes have to go looking for smaller retailers or more unusual styles. The retailers aren't always clustered together like the big chains are around Union Square. It can most definitely be challenging to know where to get started to look, and it took me a while to figure out which ones tend to stock things I like. LA even has a whole garment production industry. There's a lot of small brands based there for exactly this reason!