I usually cook for two, and don't like saving food for later (especially because an 8 serving recipe means eating that four days in the week, and the freezer is tiny). But most recipes online and in many cookbooks are for 6-8 people.
So: any general tips or guidelines for shrinking recipes? Mains, cakes, bread, whatever? What sort of thing have you found can easily be cut in half, which ingredients generally need more complicated measures?