Here are some simple and easy instructions on the proper way to fill out a tax return and avoid an audit: follow instructions to the letter, answer all questions, attach all schedules, sign and date the return; check for mistakes--math errors draw attention to your return; explain unusual items--anything out of the ordinary should be explained in painstaking detail--when in doubt, overinform; file on time--extensions are okay, but make sure you turn in your return before the extension is up; provide proof that the return was filed on time by registering the return at the post office or by having your copy date-stamped at the local IRS office; and consider electing S corporation status.