Space is definitely at a premium in my suitcase, so I like to make every tiny bit of room count when packing my bags. My favorite perfume bottles never make it on the plane, since they're pretty big (and breakable, too).
Instead of resorting to stock perfume samples on your next trip, try this tip from the latest issue of Every Day With Rachael Ray: Pack cotton balls instead. Before you go, soak a few cotton balls with your favorite fragrance and stash them in a snack-sized Ziploc bag, making sure to get as much air out as possible when sealing. That way, you've got your trademark scent ready when you are, and the little sack just may act as a subtle fragrance pouch when packed.
The same thing can work with any other liquids you apply with cotton balls or swabs (like toner or makeup remover). Just give each its own labeled baggie so the right liquid ends up on the right body part, mmmkay?