If you can take a trip, go somewhere where you will be totally immersed in English (like the States, or the UK, etc.).
Get several English-only penpals with whom you share similar interests, and start an ongoing communication.
Take a class in some art (sculpting, painting, music, acting, cooking, etc.) or other subject where the instructor speaks English only. Guitar classes with an English-speaking teacher can be fun!
Learn to sing several English-language songs (pop, folk songs, etc.) and impress friends, family, and dog.
Watch more movies in English but turn off your native-language subtitles.
There must be many more ways to make learning English fun and interesting...!