Films set in decades past are a great way to get a feel for how people of the time period dressed. They're also a great source of inspiration. Here's a little trip back in time to some films from past decades.
Grease (again, not made in the 50s but it's pretty true to the time it's set in)
Breakfast at Tiffany's
Starsky and Hutch
The Breakfast Club
Do the Right Thing