I recently ran into this. Thought of implementing a new project in clojure and quickly defaulted to the language i am used to.
One way to mitigate this is to re implement a small project that you have already implemented in your older language. At least you can focus on the language instead of the project nuances.
Another way is to pick a top-notch library or framework in your target language, and learn to use that. For Clojure, I'd try making some clever charts with Incanter:
(Incidentally, the only new language I've been able to stick with after learning Python is R, because it solves completely different problems. Which means R is now my Blub for stuff that I'd like to, given some free time, try with Clojure/Incanter...)
