What can a country do to overcome the macroeconomic problems it faces?

The answer to this depends on what problems the country is
facing.  In general, countries can face two types of problems.  They can have too much
inflation or too much unemployment.

If a country has too
much inflation, it needs to reduce its people's ability to spend.  This "slows down" the
economy and makes prices go down.  The country can do this by fiscal policy (raising
taxes, reducing government spending) and/or by monetary policy (raising interest rates,
selling government bonds).

If the country has too much
unemployment, it needs to increase its people's ability to spend.  Again, it can do this
through fiscal policy (lower taxes, spend more) and/or by monetary policy (lower
interest rates, buy government bonds).

That said, some
economists believe that what a country should do to improve its economy is to lower
taxes and decrease the amount of government regulation of the economy.  These "classical
economists" believe in laissez-faire.  They think the economy will always work itself
out of any problems if the government just stays out of
economics.