Port some small but non-trivial projects from a language you know to the one you want to learn, e.g. Clojure, since you said you are learning it. It won't be th

Port some small but non-trivial projects from a language you know to the one you want to learn, e.g. Clojure, since you said you are learning it. It won't be the same as writing a new project in Clojure from scratch, but will still help. And then, because there may be a tendency to use, in the new language, the style / idioms of the previous language you know (and ported the project from), put your code up somewhere and ask for reviews of it by people experienced in the new language.