The perfect white tank:

 

Look for a lightweight fabric that will cling to your body but isn't too sheer. The right length is also key. Find one that covers the waistband of your pants or skirt to avoid baring your belly (that look is over).

 

 

The classic denim mini:

 

A dark shade of denim is more versatile than a faded wash because it looks polished by day and dressy at night. Choose a skirt that hits at midthigh, so it's short enough to be sexy but not too tiny for the office.