Airline restrictions require all liquid items to follow the 3-1-1 rule: 3.4 ounces of liquid or less, 1 quart-sized clear plastic, zip-top bag, and 1 bag per person. This bag will have to go through security separate from your full carry-on bag. Look for travel-sized items such as toothpaste, hair gel, deodorant, etc. Also keep in mind that many hotels offer some of these items for free.
Not all items in the plastic bag have to be liquid. It is also convenient to put other travel-sized objects in this bag to stay organized, including a travel toothbrush and other necessities.