Not sure if you are mentors, or students.
If you are mentors/teachers, I would like to share some of my experience with my students in terms of writing engineering journal in general. We all know that this is not just for competition, but for any general project as well. This is extremely important experience; e.g. applying for a patent for their ideas and invention, presenting their research work someday when they are in university study, etc.
Common questions students ask: "what will be best content to write?"
Often teachers will ask: "how do I make students realized that journal is valuable, not just a chore?" The issue is more students not seeing the value of journal, they will much less likely be willing to write it. It becomes a vicious cycle.
Two out of many main issues which cause students disliking to do engineering journal:
1) do not like to write too much
2) they do not see the value
3) they see it just a chore, because they hardly look back to what they wrote
I extracted a small section out of our Instructor Handbook on Brief tips on Engineering Journal - http://www.stormingrobots.com/prod/pdf/BriefJournalTips.pdf to tackle these 3 issues.