The whole purpose is to con your friends, so the more serious you are the better, as you need to talk to your friends with a poker face and make sure you are not made. Begin by asking your friends if they want to see a cool magic trick that you just learned.
Move towards a hard, flat surface like a table, and take your friends with you. If they insist that you show them the trick right there, do not agree and tell them that the magic only works on a table or desk.
Now take some water and pour it on the surface of the table. Pour just enough water to form a small circle, around 4 inches in diameter.
Now you need to get the audience to participate and for that ask someone to volunteer. When you have a volunteer, ask him/her to pluck a hair out. You will require only one hair for this trick.
The idea is to get your friends involved and interested. Gather them close to the table and act all serious about the trick.
The next step is to place the hair gently on the puddle and make sure there isn’t too much wind blowing around.
Now, in a convincing manner, tell your friends to look at the hair carefully. Urge them to lean in and look very closely at how the hair is actually dancing on the water. If they insist they can't see anything, ask them to look closely.
When all your friends are intently watching the hair for any signs of the 'dance', you look for the perfect moment and smack your hand down on the water, splashing it all over their faces. As you friends soak, you get to watch their expressions and laugh.