According to the theory of mercantilism, what should a nation do to be powerful

According to the theory of mercantilism, a nation should regulate a nation's economy for the purpose of augmenting state power at a rival nation's expense. This was heavily present during colonial times, because the big colonial powers could regulate the trade between their colonies and other countries, therefore meaning they banned it, that way their colonies could only trade with them. This made the colonial superpowers much richer, while countries who did not have any colonies could not keep up.