People, companies and states become rich by producing goods and services with high added value. The most obvious way to achieve a higher income for an individual - investing in education, which will later become an added value you create. It's hard to become rich working as a porter (because of the low added value of your labor), and much easier being an engineer or physician.
The same goes with countries. Thus the government's task is to create it's own domestic industry (and by industry i mean technological processes that result in a product with a high goddamn value whether it be a computer game or nuclear fission reactor). That can be achieved resorting to economic protectionism, state dirigisme, it doesn't really matter. Technical specialists and skilled workers are not the problem, they can be temporally hired from abroad. That would boost domestic market and domestic demand which in turn would boost the industry even more.
But at the beginning your own economy won't be able to compete with the developed economies and transnational corporations (which have their productional and financial processes well-oiled, political connections established, highly-paid lobbyist hired) on equal terms. That's why I wrote about economic protectionism as a proper tool at that stage.
Also the reasonable strategy would be to create free-trade zones with countries with the economies of the same technological stage as it would benefit all participants thus making your economies more competitive and only after that entering a global free trade markets.
It's hard to put it shortly but from that you can see that it's somehow similar to bringing up a child.