This should only take 15 minutes. Tops.
Grab the nearest person next to you: your mother or lover (hopefully not both), your co-worker, your Maytag repair person -- whoever. Give them fifteen small strips of paper. On five of these strips, ask your benefactor to write five different Locations (aim for the ultra-specific, like a rusted sagging shack, or the flooded back room of a post office). Fold these up and place them into a sandwich bag.
For the next five strips, ask the person to give you five different Emotions. Again, aim for the specific (if it's anger, what is the anger towards?). Fold these and place them in another baggy.
The last five strips get Embellishments. Anything that adds attributes, description, and/or texture to any situation. The sound of snores, a pudding-like consistency, an elephant that snores and has pudding-like consistency. Fold 'em, bag 'em.
Now shake these baggies like a Polaroid picture. Pick a trigger from each. In one (possibly nonsensical) bursting free-write, write at least one block where all three of these things come up. None of these triggers needs to take over the subject of the free-write -- they just need to make an appearance.
(If you appreciate having created a sentence/image/moment from this exercise, please post in the comment section. I'd love to read it.)