I started out using South Dakota. I reevaluated the situation when it was time to renew my driver license. Renewal would've meant either going back to Rapid City when I was nowhere near there, or doing all the paperwork, documentation copies, and notarizations to do it remotely. On top of that, I had started disliking my mail forwarder which had started acting like petulant kids when I needed them to provide the services I was paying for (and I used them only about once a month).
In the meantime, a nomad friend had settled in Arizona, and I was in that part of the country already. She offered to let me use her address, so we created a lease document as proof of residency, got my insurance and bank accounts transferred (insurance was actually less than what I was paying in SD) and was in and out of the DMV with an new DL and registration easy as pie. Since this is in a rural county, there's no smog check. Andstate tax doesn't matter to me because I don't make enough to be taxed.
A side benefit: SD plates essentially say, "Hi, I'm one of those full-times pretending to be from South Dakota," but AZ plates just blend in anywhere in the West.
