To invest in yourself is just as important as any financial investment for your future. For both personal growth and career success, there is no telling how far you can go if you take the time to invest in yourself. Check out this video by The Art of Improvement where they explain important skills that are hard to learn but will pay off in the long run, including:
Silencing your inner critic
Learning to say "NO"
This doesn't just apply to IT contractors! Send this to anyone you think needs that push to invest in themselves and help them see the potential that you see in them.