Technically, the advice here is how to make presentation images as well as IKEA makes billboards, but I thought I wold make the more direct connection:
How to make better billboards, period.
Here are six pointers (but go here for much more detail):
1. Make it visual 2. One board, one point 3. Make type big 4. Contrast rules! 5. Use Empty space 6. Have a visual theme
Thanks Presentation Zen!