Good question, Don. My suggestions are below, but note that many social cans are kicked down the road with a broad statement about states' rights.
All powers not specifically assigned to the federal government are issues for the states to decide.
Every citizen is treated the same way as every other citizen.
The federal government may collect no more than X% of GDP in taxes, fees, etc.
The losing party in civil suits pays all costs.
All entitlement programs must be rated annually for solvency.
All government income and expenditures must appear on a single, comprehensive budget that is updated annually.
Some sort of time and money limit for armed conflicts not covered with a declaration of war.