Keep the stream of whatever interests you flowing in the L2. The beauty of the language more easily radiates when you are doing something you would be doing anyway in your native English. Playing videogames, reading novels, whatever.

One of the things I love most about learning another language is installing a second slant on the world within me. There are concepts that exist in certain languages that, like good art, reveal another dimension in your world. This is one of the reasons I would love to learn an East Asian language. Being able to experience a totally fresh world of beauty, like Chinese poetry and art.