Just pass a ballot proposition that limits the increase in state spending each year to the following formula:
CPI + (Estimated) Population Change (%)
It’s not perfect, but it would essentially keep state spending per capita constant in real dollars (roughly, that is). Had we done this a decade ago, we wouldn’t be in this mess.
Edit: In addition, the nice thing is that this would allow the state to spend more in years when the economy sucks (that is, run deficits) because surpluses would build during the good years. In other words, it would allow for fiscal flexibility when needed, while not allowing such “flexibility” to grow ad infinitum.