The federal budget is a monster. Even with tens of thousands of bureaucrats, no one seems capable of controlling, let alone monitoring it. However, I am opposed to the to a Constitutional Amendment to force balancing it. Both the President and Congress must be able to act when events occur that need intervention.
Therefore, I believe that the budget should be set based on the revenues received by the federal government in the previous year. Emergency spending could be authorized when events, such as 9/11, cause the need.