Before doing the exercise, you should read The gist of the matter.
Describe an object, selecting adjectives, participles, and participle phrases suitable for the noun.
The Announcer says: "Chair"
The Spokesperson says: "Wooden, white, pretty, broken... thrown out the window, wet from the rain, sawn into pieces, drawn on the wall..."
First variant. Each partner names an attribute, taking turns.
Second variant. You speak, the partner listens, then switch for the next word.
Speak loudly and decisively.
Before pronouncing the words aloud, try to imagine the attributes, recollecting your real world perceptions of them.
Increase your speed as you practice. Bring your speed up to a level at which you no longer have time to think up the attributes, and they start to "be born" on their own, without any effort on your part.