The rule of this exercise is to write quickly, spontaneously.
List five each of the following: hobbies that sound fun, classes that sound fun, things that you would never do that sound fun, skills that would be fun to have, things you used to enjoy doing, silly thing you would like to try once.
Or describe an interesting face in a photo. Use a picture from a magazine or a photo of someone that you don’t know. Go beyond physical description.