1. A product approach? A process approach? Which approach do you prefer? Why?
I think that I tend to combine both product and process approach, it depends.
I like using warmers and letting the students discuss first and offer ideas, and also share their own writings; but in the end I believe in form and structure too. These tools will be definitely needed, not only if students want to pass their course before university but also for less "serious" pieces of writing such as notes, informal letters or anything we want others to read. There are also different types of writers: Some people just start writing and are able to link ideas in a natural and often successful way; other students need more help. I think that we have to adapt to different abilities and needs too.
2. In what contexts might one be more preferable than the other? For example, think of teaching children, teaching businesspeople, teaching English for academic purposes, exam preparation etc.
I only teach teenagers and young adults so I suppose that my work has nothing to do with, for example, teaching small children. In that case a process approach would be probably more convenient. If we are teaching to pass an exam we normally worry a lot about accuracy and structure, but this should not mean that we have to reject a process approach.