Here's an example of one of my vision boards. I have several of these and if I can unearth others from storage, I'll share them too. The most important aspect of this assignment is not just having a specific "vision" but pairing that vision with the feeling of having or attaining what's on the board.

For visual artists, a vision board probably feels natural but there are other ways to do it too. Choose the method that feels right for you. Another one I've discovered is the 10-year plan. If you Google "10-year plan by Milton Glaser," some links should come up that show you how to do it, step-by-step.