Make sure your tax preparer has all the necessary credentials to do your taxes correctly. It is important that the person is also informed of all the new IRS laws.
Make sure your tax preparer is available all-year-round for any questions or information you need. It's not worth paying $100-$180 to have that person disappear later when you need them.
Make sure your tax preparer works responsibly and legally so that you don't get into trouble with the IRS. If false information is filed, the IRS will look for YOU to give you a fine.