There are a lot of federal buildings and properties that could be sold to pay down the debt.
And opening up mineral rights, fishing rights, logging rights will generate income.
Letting people who already HAVE rights and leases would do a lot, from oil drilling to mining to fishing. That would boost the economy and create jobs.
I think the Capitol Building needs turned into a museum with enough tours to generate money to keep it open. All Congressional offices should be sold. A college or university could use them for offices, classrooms, and/or dorms. Congress members should have to live, and not just have a home, in thier districts (obviously just the state for Senators). They can have one office, one secretary, and mailing privileges paid for by us. With modern tech, debating and voting can be done via telecom services. It can be live streamed. Easy peasy.