Tax preparation is often a very stressful process.  Worry and tight time deadlines can lead to mental errors with big repercussions.  Before you begin preparing your taxes you should gather all of your receipts and statements.  Find a quiet workspace with a lot of room to spread out.  Take your time and give yourself more than one day if necessary.  The following are common tax mistakes made by US taxpayers:

1. Late filing – not filing on time will result in late fees and penalties
2. Incorrect and missing information – this can cause the IRS to delay acceptance of your tax return.  It may also result in rejection of your return.  
3. Math errors – do the math twice to ensure accuracy
4. Not keeping up with recent tax law changes – US tax law is extremely complicated and changes often.  Failure to stay up to date on tax laws can cost you.
5. Not keeping a copy of the return – A variety of situations require you to have your tax return, for example IRS audit or buying a new house.
6. Lying – don’t give in to the temptation of hiding income or falsifying deductions.