Thank you for sharing this interesting topic.
The samples you wrote about is a good challenge for someone whose proficiency level has reached lower intermediate level.
For those who are still at absolute beginner level, writing simple daily life posts is a good start.
Translating articles that are written in native language into one's target language could also be a challenge.
Composing a dialogue from scenes of the part of a story could be a mean of practising spoken expression.
In a word, to be a good writer, one should have a good reading habits, grasp an immense of vocabularies, and know how to use them.