I haven't done a lesson about the General Writing test for a while, so here's a recent exam question that a student sent me. I'll share my answer next week.
Remember that the examiner is looking for the following things:
- The tone must be appropriate (formal or informal)
- The purpose of the letter must be clear
- You must cover all of the points
- The letter must be well-organised
- You need to use some good (and relevant) vocabulary