In a recent case, executors of an estate were held personally liable for the unpaid tax lien on their parents' house. The planning tips from this matter are:
1. Make sure your parents pay their income taxes,
2. Feel free to decline to serve as executor,
3. Pay income tax obligations before paying other debts, and
4. If selling an asset, do not reinvest the proceeds in a risky asset so that there will not be any liquid funds if the IRS comes looking for payment of its lien.