A chignon usually starts with a ponytail and is rolled under in the back. Diane is sporting one at the 4th Annual Behind the Camera Awards in Hollywood.
This is a classic style with a hint of vintage. A banana clip across the hair in the back can be a good start. Hairspray along with pomade are good styling tools to help hold the shape. Accessories can be used to hide the clip. A side bun can also be done to get a look like this. Start with a ponytail and roll under and clip with bobby pin. Pin up stray pieces after.