What does it take to build a country after declaring independence?

One can think of many things that a country must do once it is considered independent.

To choose a government system that pleases all or at least, the vast majority of the citizens, elect a chief of State, elaborate a new set of laws and many other things that are basic to live in a society under the power of a State.

Also, it's very important to consider that since the United Nations was created, it has become first step to receive international legitimacy.