That's pretty much it, but if you want to get there fast, just attack and take a castle or town of any faction and take it, while not being in a faction. But you should be uber badass first, since when you do that, any faction can attack you. So... yeah. I'd prefer Kusky's way. Oh and when you do it my way, your faction becomes named "(insert faction name here of which settlement you just took) Rebels", but I think the same goes for Kusky, not sure.