Why not encourage your student to keep a daily diary that they are happy for you to check every couple of days.
Diaries allow students to be creative, reuse new vocab and allow you an insight into what your students find interesting or noteworthy. It also lets you monitor their written English.
If the student is happy, you can of course comment on the diary in terms of content, vocabulary or structure. However it may not be best to correct every mistake. Writing, like speaking, needs to be able to flow.
Diaries should be written in the student’s free time, either in late afternoon or in the evening.
Have your students kept one?