Do one thing every day that scares you.Eleanor Roosevelt
This is great advice for everyone. I see almost everyday in working with software developers we all have different opinion of what things we can consider. Perhaps we need to try a new language or learn a new library. Some where in the future that may come in handy. It could be as simple as talking to someone new and learning what they do or going to the User Group meeting and learning about some new technology. Look at what have done today and see if you are getting challenged or scared. If not push a little harder.