Here's a good one.
In the process of a business deal, send two copies of a form requiring in a package to the other party.
The other party sees a duplicate, ignores it, and returns only one copy, and retails the duplicate copy in a pile some where.
Later, after some time, request that they send you the duplicate form for the first time. Be sure to indicate that this missing document has delayed all processing.
The other party flips through the pile, and sees that he didn't send it, admits to missing it, and returns it signed along with acquiescence to a delay in processing or completion of contract.
