I've just been to Boots and saved a bit on make up. There are currently two separate offers on L'Oreal cosmetics - 3 for 2 on L'Oreal cosmetics and a £2 off voucher which is redeemable against any L'Oreal product. I had two £2 vouchers which was accepted against the 3 for 2 when scanned at the till.
Nail polish FREE (should have been £5.86)
Minus the vouchers (£4)
Total was £10.98 - so in total combining both offers I saved £9.86!
Great if you have one or more of the £2 vouchers kicking about.