Fraud analyst here---
Document what you claim re income, expenses, contributions, deductions, credits, etc. Period. The IRS/state DOR might flag you for any amount because amounts are only one aspect of why a tax return is flagged. If your documentation is questionable or non-existent, that casts more doubt on your return than some amount threshold. Some church-goers give extremely high amounts of their income to their church--much more than is seen in the overall population. Full documentation helps. Some people give a disproportionate amount to a charity following a crucial life event, e.g. loss of a loved one. Full documentation helps. The Internet can help you understand the level of documentation that is needed. You can also call the IRS/state DOR anonymously and ask specific questions.
Pay what you owe but no more. That's neither tax evasion nor tax fraud. That's tax smarts.
