Introduce a balanced budget amendment that requires the first 10% of all spend to pay down any existing debt. The rest of the the spend should then match the remaining actual revenues from the prior year. The congress can modify the spending mix (what percent goes to which agencies), and 10% would be discretionary. There could be no overspend without a 75% majority of the congress passing it (for dire need).
The amount each agency gets would thus be fixed based upon the prior year revenue.
We the people are tired of a government that spends our money beyond our means and is leaving our children a legacy of debt. A strong fiscal discipline is needed.