Kites in prison are something big. The kites are used to send messages, including contraband such as drugs or even blades - during a block lockdown or in the Isolation. The easiest way to make a kite is by using the fishing line method, using a piece of linen cloth that you would most likely tare apart from your bed sheet, afterward you will attach it to some item such as a small piece of cardboard taken from a milk box or even an empty tube of toothpaste, as long as the object fits beneath the door.
Once you have made the kite you will need to send it towards its destination, most likely sending the kite to your neighbor. In some cases, the receiver will need a hook so he can grab the kite as it could take many attempts to land in the right cell. Also when you are going to send a kite towards someone you would usually ask the person if he is "able to receive mail" so you don't cause any issues with other races and so on (landing in the wrong cell).
Most of the times when a person lands in Isolation he will be around all the big players, this is their house so you will require to show them respect, this means that if you wish to send your 114, you will have to ask for permission, something like this "Excuse me on the tier, X are you able to receive mail?" While your stay in the Isolation you will have to show respects to all the inmates, saying please, thanks and so on. Usually when the kite lands the person will say "Touch down!" which means that the kite has successfully arrived.
The last person to receive the kite will have to flush the kite in the toilet so no tracks are left behind.
Some videos that I found on youtube explaining the entire process.