Breaking news ... Lauren Conrad IS funny! The fashion maven and former Hills hottie recorded this hilarious PSA on FFP's ... also known as Fashion F**k Ups.

Conrad talks about everything from letting your friend walk out the door looking like a wreck, the horrors of jean shorts ... and the "dumb" kitten heel. She says the ONLY person who can pull off this shoe is Suri Cruise. Loves it!

She offers the following advice: "Take off the training shoes and stretch your stuff the way your plastic surgeon intended."

Oh, Lauren ... you made our day.