Another great small bottle find that adheres to TSA rules are extract bottles. An empty vanilla extract bottle is perfect for small amounts of liquid - just be careful as many are still glass. McCormick bottles have also started using flip-top lids, which may not be as secure as the older screw caps so be sure to properly wrap these bottles if used.

Almost all hotels provide small 1-2 use samples of shampoo, bar soaps, and even sometimes conditioner, lotion, and mouthwash right in your room. These are free to use and take home, and you can often request any forgotten common items from the front desk (though sometimes for a fee). Higher end hotel chains will even have brand-name samples waiting in your bathroom.

Don't forget that many companies offer sample sizes of their new products to get consumers to try new brands and items. There are plenty of free sample sites like Shop4Freebies that list sample-size offers from around the Internet. Even large retailers such as Walmart have created free samples and savings pages that let consumers request samples of new and featured products. These samples are often mini-versions of the full thing - perfect for travel!