It's much easier to detect funny smells on other people's clothing than it is with your own wardrobe. For this reason, make sure your interview suit is freshly laundered. Make sure your clothes have no stains or discoloration, and check for a yellowed collar, stained sleeve cuffs or even bleached-out spotting.
Unless you're interviewing for a job at a cigar shop, don't wear anything that's been near tobacco smoke or drive to your interview in a car that's been smoked in regularly. Also, make sure there's no animal hair on your clothing. Remove it using a lint brush or sticky roller. Even freshly laundered clothes can look or smell dirty when they're covered with smoke or pet hair.
Clean clothes are a must, but you should also clean and polish your shoes. You don't need to see your own reflection, but you shouldn't see an artist's rendering of the dust bowl either. Pay attention to your other accessories, and make sure your handbag or briefcase is clean on its exterior and organized within. It's pretty awkward when you go to retrieve your CV and have to empty all the contents of the bag in your lap to find it.
Finally, don't eat on the way to your interview. Driving and eating often leads to frantically trying to get a ketchup stain off your shirt in a public restroom.
You've got magic in your fingertips, but also dirt from the garden. We'll give you a hand with that in the next section.