Someone asked me the other day where to get some good prompts from. Just thinking off the top of my head, I told him try using song lyrics (okay, so I write song lyrics). Then I started to think of the various ways people in our group do come up with ideas for prompts.
There are various books available that will give you some great ones. Natalie Goldberg's Writing Down the Bones has several ideas. You can get ideas from:
lines from songs
sentences from books and magazines
use weird words from the dictionary
photographs or pictures from magazines
phrases you overhear in the coffee shop
things your kids have said or done
In short, life is one big prompt. Ideas for prompts should be simple so the writer can feel free to run with whatever crosses their minds and not feel restricted.
There is always something to write about.