Learn to ask yourself questions about everything. Ask "what if", "how", "who" about some of the things you see. An example when seeing an old house being torn down: I wonder who has lived there over the years. What if they find that there was a secret room in the basement while they are tearing it down. What if they find a painting that was stolen in 1892? Or, what if there are skeletal bones in the room? Or, what if there are lots and lots of (you fill in the blank)--where did it all come from, who put it there, who lived in the house in it's past that would leave that and why? (Sure this will make a better story than a poem or song but it all works the same). One night I saw a man asking for change outside a restaurant. He didn't even have a coat or long sleeved shirt on and it was cold, just a used-to-be white tee shirt and a raggedy pair of dirty pants. He had a raggedy backpack on his back and a holey stocking cap on his head, but he had a brand new pair of high dollar shoes on and minty fresh breath as if he had just brushed his teeth. The inconsistencies of his appearance made me wonder what his story was, it also made me want to 'give' him a story to fit what I was seeing.
With thousands of stories, songs and poems going on around you every day, snatch a few out of the air, ask yourself questions and put those stories, poems and songs on paper.