If leaders wanted to create a government that was more effective than the government under the Articles of Confederation, which is the most important idea that should be embraced?

The most important idea that should be embraced for more effective government under the Articles of Confederation, is the national government cannot be weak.

Explanation:

The major cause for the Articles of Confederation to be ineffective was the federal government, was too weak to enforce the laws and they had no power to impose taxes. They allowed state governments to levy taxes.

For its expenses, the national government had to request money from the states resulted in major disputes within the states, laying taxes and the national government is restricted to interfere in those issues as major powers were with state governments.