Knuckle cracking is satisfying and gratifying to those who enjoy it, and aggravating and disgusting to those who don't. If you're interested in being a creative knuckle cracker, you can learn multiple ways of going about it. People have different opinions about the health effects of cracking your knuckles, with some people claiming that it's harmless and others insisting that it contributes to problems with arthritis.
The Classic Method
You may recognize this method from old gangster movies where tough guys would use it to limber up their hands before beating someone senseless. Hold your hands up with the palms facing away from you and interlock your fingers. Now push your hands away from your body so that the back of each hand bends the fingers of the other hand backwards. Keep pushing until all your knuckles crack.
This method allows you to select the knuckles that you would like to crack. Hold the upper end of a finger tightly with your opposite hand in a fist. Pull on the finger until the knuckle cracks.
This method could also be used as a form of torture, so don't overdo it. Hold up a hand with the palm facing toward you. With your other hand, grab one of your fingers and bend it backwards over the back of your hand. If it starts to hurt badly before the knuckle cracks, stop or you may break your finger.
Hold up one hand with the palm facing toward the floor and make a loose fist. Wrap your other hand over the top, with the first row of knuckles of each hand aligned. Squeeze your lower hand tightly with your other hand and pull down over the fingers until your knuckles start cracking.
This is a dramatic method with excellent visuals. Place your hands in front of you with the palms and fingers together in a praying position. Lift your elbows into the air and force your palms apart until the backs of your hands are horizontal but your fingers are still vertical and pressed tightly together. At some point, your knuckles will start to pop.