I don �t think this is particularly helpful but I think its worth trying.
Make a list of words on the same level as the students in your class. (about 20 should be enough)
Ask the students to make partners.
Each student is to make an original story/essay/article, with 3-4 words included in your list on the topic of his or her choice(make sure they don �t choose the same topics), give them about 3-4 days for this.
Next tell then to switch with their partners, give them 1 day for correcting their partners mistakes(with a different coloured pen and highlight the mistakes).
Finally after this collect all the reports and check the usage of your words, also check the highlighted mistakes.
This way you can test your students twice(once for writing and one for correcting).
Now I don �t know if this will be possible but in my opinion it gives great writing practice.
Hope it helps.