One tip that's not specific to LLCs but that I nearly missed: don't forget to check if the city you're based in has its own business licensing/taxing requireme

One tip that's not specific to LLCs but that I nearly missed: don't forget to check if the city you're based in has its own business licensing/taxing requirements. For example, in San Jose you need to pay $150/year for a "business license", even if you're just working from home by yourself.