Tutoring for Business Correspondence

I've just started tutoring a young woman in Business Correspondence. As a non-native English speaker, her main concerns are presenting messages to her colleagues via e-mail, reports, and presentations that are grammatically correct, concise, well-organized, and effective.

Each session begins with a lesson on Business Writing, i.e. how to write concisely, or knowing your audience, or setting the tone, etc. SkillSoft offers two modules on the subject of business writing. Then the student completes exercises from a grammar workbooks to practice targeted skills. Finally, she applies her skills to business correspondence she intends to transmit and/or evaluates correspondence she has already prepared or transmitted.

Questions for discussion:
1) What other learning materials have you used to support the goal of improving business correspondence?
2) How to measure your student's success?
3) What challenges may be unique to ESL students? (Business idioms? We sure use these a lot in my regular job!)
4) Other?

I welcome your comments, questions, and thoughts!