We’ve teamed up with Saks Fifth Avenue and social networking site Foursquare to offer you styling tips on the latest trends while you shop, plus the chance to score a free lipstick from Nars! Sign up for an account at Foursquare.com, follow InStyle, and download the free app to your smartphone. Then take these three steps:

1) Visit a participating  Saks Fifth Avenue store in Atlanta, Beverly Hills, Boston, Chicago, New York City, Phoenix, San Francisco, Short Hills, NJ, or Troy, MI.

2) Check in at InStyle-branded hot spots located in four departments throughout Saks Fifth Avenue—in Shoes, Beauty, WEAR and Women’s Contemporary—to unlock exclusive shopping tips from InStyle editors.

3) After visiting two or more hot spots, head to the store’s General Manager’s office, show off your check-ins, and nab that new Nars Pure Matte lipstick (while supplies last)!

Stay tuned through December for more check-in gifts from InStyle and Saks Fifth Avenue!