Instructions
Determine the joke/prank you plan on making. The key to a good prank call is coming up with a premise that the recipient will fall for before realizing the call is a prank.
Determine the recipient of your prank. It is a smart idea to keep the prank calls to friends and family members. Prank-calling the wrong people can land you in trouble.
Dial "*67" before dialing the phone number of the recipient. This prevents your phone number from showing up on the recipient's caller ID. Not only does having your name show up on the caller ID ruin the believability of the prank, but it also immediately reveals your identity.
Disguise your voice when talking. Whatever you do, don't laugh mid-prank --- that's a dead giveaway, and the recipient will likely hang up.