Go and look out of your window right now. What can you see? Rain, winter trees, the grey sky reflected in someone's window? Have a good look and choose one thing. Don't spend too much time wondering whether it's right or not. Just choose one thing. Using this as a starting point, free-write for 20 minutes allowing your creative mind to take the routes it chooses. Let it run.
When you've finished, close your notebook. Don't read over it.
Using the same starting point, write for another 20 minutes tomorrow.
Do the same again the next day.
If you can, aim to do it every day for a week. Or at least every other day.
At the end of the week read through everything you've written. You might find the seeds for a poem here. Maybe not. I believe that it's only a small portion of our writing that's actually worth making into 'art' for other people. But you'll still be able to extract something from this exercise. What matters to you. Look at what you've written - the themes, the ideas, the emotions behind the writing. Make a note of them. This could be where your passion for writing lies. Follow it.