Give taxpayers the opportunity to directly affect government spending decisions. For example, 5% of gov't income tax revenue could be distributed per the direct wishes of taxpayers. One mechanism could be a question at the end of 1040-type tax forms: "How do you want the 'taxpayer-directed' portion allocated to spending areas x, y, z?". So if someone paid $4,000 in income taxes, then $200 of that revenue could be spent exactly as the taxpayer indicates...split between areas such as education, military, health, science research, transportation/infrastructure, etc.
This could lead to an Empowerment Revolution if people start to feel more engaged with where our country is headed.