I always use brainstorming to kick start me if I am stuck. Brainstorming means writing absolutely everything down without any censorship. Even if it seems unrelated, it may well fire up some other ideas.
The idea is to get your right brain which is your creative side into play. Writing is a left brain activity, and that is why we sometimes get stuck. So getting the creative juices flowing by engaging the right brain is a good way to overcome writers block.
Then I pad out those words or ideas into sentences or paragraphs and then organize them into topics or groups.
That way you usually end up with a wealth of material to use.
Hope that helps!