Always put extra paper clips on your forms. Any foreign fasteners or the like have to be removed and put away.
Always put staples in the right hand corner. Go ahead and put them down the whole right side. The extractors who remove the mail from the envelopes have to take out any staples on the right side.
If you send two checks, they'll have to staple your unsightly envelope to your half destroyed form.
If you're very unfortunate and have to pay taxes, send two or three party check. On top of paying with a third party check, pay one of the dollars you owe in cash. When an extractor receives cash, no matter how small an amount, he has to take it to a special desk and fill out of few nasty forms.
Line the bottom of your envelope with Elmer's glue and let it dry before you put in you forms, so that the automated opener doesn't open it and the extractor has to open it by hand.
Never arrange paperwork in the right order, or even facing the right way. Put a few upside down and backwards. That way they have to remove all your staples, rearrange your paperwork and re-staple it (on the left side).
Sign your name in ink on every page. Any signature has to be verified and then date stamped. These are just a few of the fun and exciting things you can do with the IRS. These methods are ONLY recommended when you OWE money.
When you mail it, mail it in a big envelope (even if its just a single EZ form). Big envelopes have to be torn and sorted differently than regular business size ones. An added bonus to the big envelope is that they take priority over other mail, so the workers can hurry up and deal with your mess.
Write a little letter of appreciation. Any letter received has to be read and stamped regardless of what it is or what it's on.
Write your letter on something misshapen and unconventional. Like on the back of a supermarket sack.
If they owe you money, being nice helps.