CR has 8% cash back on Beauty at Myer. If you're a fan of Lancome, stack with their offer of additional gifts with purchase of $75 or $120 respectively.
If you prefer straight cash back from Lancome, it's currently 15% back, usually 5.4%
YSL has 15% off site wide and 10% cash back. (I like the YSL libre perfumes), usually 5.4%.
Side deal: adore beauty, if you like YSL, spend $120 and get a 6 piece gift.