The spring 2009 runways schooled us on just how seductive sheer can be. If done correctly, it perfectly channels a subtle sex appeal that is as mysterious as it is romantic. If done incorrectly, it looks like, well, Gerri Halliwell mooning a room full of children (had to!). Here are a few tips to ensure you don't pull a "Gerri" and some celeb inspiration for all ages.

Tips on Getting Sheer Right:

• Full on sheer is inappropriate anywhere other than the bedroom.

• It looks best done on top, rather than a see-through bottom.

• Choose a neutral hue (black, white, navy) to keep the look chic. Shy away from colors like red which will look cheap and cheesy.

These celebs use the trend to reveal just enough to keep your wanting more.