ziplock bags rule. Use them to pack everything.
Put your underwear in ziplock backs so when security goes through your bags, they won't have to touch your underwear.
You can put items in ziplocks and suck the air out through a straw to compress clothes.
Put shampoo and other liquids in ziplocks to prevent spillage in your suitcase.
Use ziplocks for any small items you don't want lost. Ziplock up your chargers and adapters.
roll your clothes and remember how your suitcase will sit...pack breakables to the top and back of the suitcase, heavy items and "crushable-friendly" on the bottom.
Tie a ribbon or put orange reflector tape on your bag to identify it at the airport carousel.
Keep your cash in separate pockets and always just keep $2 in one pocket for tipping the same amount all the time without being compelled to over-tip a bellhop or skycap.
Carry your own pillowcase, or pillow to prevent allergy problems with the hotels. Carry a small bottle of antiseptic cleanser for hotel bathrooms and phones.
Drink water and juice for flights...they are nothing more than dehydrating germ bullets in the sky. Carry gum and a small bottle of lightly scented hand moisturizer. Chew gum for the ear popping, and put hand cream on just after takeoff. Someone always has gas and stinks up the plane, you can sniff your hand and not get sick from the smell.
If you can check it....check it! Don't carry more as a carry-on than you need to. If you are changing airlines, maybe reconsider checking a bag as the risk of losing it increases.
Wear slip-ons and minimal jewelry to go through airport security.
If going on a long trip, carry a wardrobe that is interchangeable, then carry 1/2 the clothes for the whole trip...and use the hotel laundry service.
Join the frequent flyer programs. Even without miles, being a member offers benefits and considerations.