Step one place him/her one a computer keyboard. Write down which keys he/her presses.
Step two wait a few hours away from him/her. When you come back see what she/he is doing.
Step 3 What were they doing? If it was sleeping give a short lazy name is using the letters you wrote down a while ago*. If they were playing give them longer playful names with the letters you wrote down*.
*feel free to add a vowel if necessary.