Two things:
- If you're working on writing skills, it's bound to be less natural (grammar and all)
- If you wanna express yourself more naturally, work on speaking skills. For that watch movies, practice....

One thing (there are a bunch of): Look for a Facebook group or fan page in English, it can about your favorite TV show, singer or band; but the thing is to see how native English speakers express themselves through the comments about different topics. 

italki is a good source for you to improve your writing skill.

Read with understanding as much as you can,. Reading automatically helped improving my writing. When you write you have to imagine, you imagine ideas organize them and write them down and then you arrange them as a neat message or paragraph