Post Declaration of Sovereign Territories
Once you or your tribe lawfully established a sovereign micro-nation, the work starts. You would need some form of authority, council or society to issue certain documents, like the Republic of Good Hope in southern africa or Terrania of the germanic district. Here you start designing passports and other documents, also don’t forget to de-register anything else from the old parent system, like companies, private conveyances or other moveable property and your own legal entity aka CITIZEN.
Currency, money and exchange are another vital aspect, assuming you want to break free from the fraudulent FIAT money system. There are now many new concepts and ideas available, i.e. time banking, talent exchange, crypto currencies, barter and gifting economy, see some in the useful links section
Depending on the size of your nation and number of people, safety and security is another, often difficult issue. While the new earth envisions a world without conflict, the question about firearms remains. A martial arts trained militia with some weapons is probably required, not only to defend the nation from any possible exterior threats, but also internal; similar to the american constitution, which authorizes its people to remove any government gone rogue.
What form of management works best ? Government, democracy, republican, monarchy, benevolent dictator, council of elders, minority rule, anarchy, self-governance ? Considering that micro-nations or communities should not grow larger than 5000, the need for a government per se does not really exist, nor anything centralized. Explore new and old ways of decision making and conflict resolution.