1) Find a piece of land nobody wants or has claimed yet 2) Design a flag 3) Erect a flagpole
Option B:
1) Muster an army 2) Claim a piece of land 3) Defend it
For instance, some guys tried to colonize an island that was just around sea level in the south pacific. The king of the next island over found out about it and sent some big guys over to beat them up.