With season four of Mad Men premiering tomorrow, we thought it was a good time to reflect on episodes past — as well as taking a looksee at some new episode stills — and the salient lessons gleaned from our favourite quietly ruthless New Yorkers. Joan, Peggy and Betty may not be the most psychologically stable bunch, but they sure know their way around a vanity table. From lipstick advice to wielding the ultimate power bouffant, check out these 10 all-important beauty lessons from the ladies of Sterling Cooper Ad Agency.