One of the thing I'm working on now is a series of poems about each of the elements: earth, air, water, fire. I think a good exercise might be to find some categories like that in the world, especially ones that oppose each other in some way, and use them as inspiration. For example, you could write a poem each about yellow, green, and red, the colors of a stoplight. When you think about it, you'll have plenty of associations about each category; for example, yellow could remind you of lemonade, leading you further to the stand you used to have as a kid. Or red could make you recall candy, then the suckers you get in doctors' offices. Another example of categories would be each of the pieces in a monopoly game, like a race car, top hat, dog, etc. When writing each poem, think about how they respond or allude to one another.