One exercise is to write the worst possible poem. This gets you unstuck a bit. You have to resist the temptation of writing it too well or even too badly. It's difficult to explain, because you're not writing a poem that is hilariously bad in every way, but one that might be almost someone else's idea of a way to write a poem.
The idea is to jar something open that wasn't open yet. If you say it's a deliberate attempt to be bad nobody can criticize it. It might even have something accidentally good in it or at least point in that direction.
I associate bad poems with similes, with long shapeless lines & arbitrary enjambments, and with inert language, so here goes:
My mind is an interesting place to live—more than yours,
I think. But saying it like that makes it less true. Not just the dumb bragadoccio of it, but
the ignorance. I’ve never been in anyone else’s mind! What’s yours like? Mine
is uncomfortable, choppy like choppy seas, but at the same time arid. What smells
are in your mind? Is it a theater, a living room, or a clearing in the woods?
Is it dark in there? Is it damp and sticky like mine, or does it get ventilation?
Has it been cleaned out recently? Has it been graced with a new idea? Also,
living in a mind is a small, sad thing, I think. Everything there is a goddamn metaphor for
the physical world where we really have to live. That is not so interesting,
is it? That lack of materiality, like a soup in a dream that has no actual taste.
Thinking myself superior to someone else because my mind is more interesting is
garbage. Just because it has some fragments of music that you are probably hearing too…