1. Find a challenge group - many social networks like Gather have them and write to the prompt. It works!
2. Find a writing group in your home town and join it. Preferably the one you choose will share their writing every week so you will be motivated to have something to share yourself.
3. Think of a word or phrase, anything, and challenge yourself. Write a story or a poem or even an article around that word or phrase. Don't think about what you will write when choosing the word - just look around you and pick.
4. Read the headlines and/or the current news. Write about something that raises your blood pressure. It can be a blog, an article or even a fiction story.
5. Enter a contest. This one will really get you going if you're up for it, especially a contest such as the National Novel Writing Month (NaNoWriMo) or Script Frenzy where you have a fixed length of time to complete your work.
6. Look at a piece of art or a painting and imagine the story being told by it. You could write a story, a poem or even a whole manuscript!
7. Go through your old work and write a sequel, even if that work is a poem you can follow up on the story it was telling or the emotions it was describing.
Now - to take my own advice!