Start writing. Sit down in a comfortable writing place, where ever that is for you, and just start writing. Write about what you see in your space. If you are out in public, say at a restaurant, write about the people in the restaurant -- what they are wearing, funny things you overhear, intrigue (real or imagined). Don't worry about working on anything specific, just get your thoughts down on paper. Then sit with them for a bit and whatever sentence or paragraph catches your attention, expound upon it.
Or write in a different form. If you write prose, try poetry. Take a picture and write a few paragraphs about the picture. Use your imagination. What is happening in the picture that you can't see?
You will be back to writing in no time.