Secret no. 1: They know when you're just trying to snag a free sample

When I see a beauty counter salesperson giving out free samples of something (say, an eye cream), I'll "curiously" approach her and take a few packets, acting as if I've never seen eye cream before. I'm sure you've done this too. But here's the thing: They know exactly what we're up to.

That's why most salespeople will only give you about three days worth of product, max. "We are not supplying their skin care, we are just letting them touch, feel, and smell," says a former counter worker. And "some beauty advisers won't waste product on someone who won't buy," she adds.