Overall development of a country largely depends on the economic policy instruments particularly fiscal and monetary policy to streamline the development and continue the developmental progress. These two policies have significant effects on long-term growth. It is noticed that policy adoption and reforms in both fiscal and monetary policies undertaken by Southeast Asian nations during the 1960s through 1990s have contributed to their advancement. This paper discusses the strategies for flourishing as emerging economies. Examples from Singapore, Thailand and Vietnam are highlighted in this study. It is found that prudent fiscal and monetary policy, effective discounting and interest rate; modernized tax system and most importantly policy regime are the contributing factors of these emerging economies. However, in spite of high-income growth and development because of supportive these policy initiatives, administrative and politico-economic constraints challenged the path of economies. Long-term development strategies are suggested to sustain the growth and continue the development pace.