Advent season is officially here - and as someone who’s already opened more than I’d like to admit, I can confirm: The M&S beauty advent calendar is always one to watch. Each year, it sells out fast (and for good reason), landing a solid spot in our best beauty advent calendars round-up. “I’ve been a beauty writer for over six years, and in that time, I’ve opened, tested and unboxed more advent calendars than I can count.