For organisations I have been running courses in official writing for many years. Several organisations have tried it and come back for more. I also run public courses in writing for the Institute of Chartered Accountants in England and Wales.
Delegates send in advance a sample of their work.
I analyse this in constructive detail and hand back a confidential typescript commentary. This private tuition is one of the most useful parts of the course. Your commentary will not suffer. It saves time if you have a copy of my book The Business Guide to Effective Writing published by Kogan, price 7.99. If you want a copy and can't get one ask me.