Local: Vote for doing the right things. Vote against doing things the wrong way.
State: Vote for public schools, for health care, for water supplies, for women, for voting rights, for paying for government, for science and fact-based government.
Federal: Vote for jobs, for Medicare and Medicaid, for health care reform, for Social Security, for paying for government, for a carbon tax, for financial regulation, for civil rights, for the environment, for immigration reform, for Keynesian economics, for science and fact-based government.
Most importantly, vote, while they'll still let you. ;-)