I learned this from playwright Suzan Zeder. It's a great way to stimulate creativity, get over writer's block, or whatever. It's amazing what even normally less facile students come up with during the writing part of the exercise.
These are the instructions I give the class:
In a moment you will go outside for a walk. You will walk very, very slowly. (This works better if the place you send them to walk in is not too crowded, because they will attract attention. If you're working with students during the school day, it's also best to alert the powers that be, so that the students aren't stopped and asked why they're not in class.)
Don't concentrate on trying to memorize what you see, and do your best to ignore any stares you might get from others.
You will walk for about twenty minutes.
While the class is gone, I get the room ready for their return. I dim the lights, and, if possible, light some candles. I turn on soft music. (Debussy or the like seems to work best--something like "La Mer.") I put several sheets of paper and a pencil in front of each chair. I write a few Haiku on the board, to be used as examples of the form. (I've included a few examples of my own Haiku below. Technically Haiku are supposed to be about nature, but all I stress is the rhythmic form--three lines of five, seven and five syllables.)
When the class returns, I quietly instruct them to take their seats. I tell them they are now to write Haiku about anything they like. I point out the examples on the board for those who don't know what Haiku are. (I generally have to give these instructions over and over again, as the class straggles in one at a time. I try to give them exactly the same way each time.) I don't mention the lights, the candles, or the music. If anyone asks questions, I refer them to the instructions again. They are to sit and write Haiku.
I let them sit and write for about ten or fifteen minutes--or until they seem to run out of steam. Then we share the Haiku.
That's all there is to it. It works, though. Try it!
(All of these were written during this exercise, the first time I did it at a workshop conducted by Dr. Zeder in Houston.)
Swimming with the stream,
Rushing forward, clutching tight.
No one look at me!
Space is an elevator,
Sunshine a window.
Many lovely rocks
Decorating the sidewalk.
(Some of them are gum.)
Watching from a tree,
Bushy tails contemplating
All the idiots.
Clumsy, rushing tenements
Falling up to God.