Elevators buttons pushed by unruly children?? Push each button twice and it wont stop at those floors!
Don't have a portable DVD player or tablet? Place your cell phone in a sandwich bag and hang it from the tab on the tray table that swivels from side to side. Just slip the ziplock side under the tab.
Pack each outfit in a freezer bag. Don't want to dig through your suitcase or duffel to pair up clothes? Pair them up ahead of time in a large freezer-size plastic bag. Include underwear, accessories, and anything else needed to complete the set. Then you just grab the bag in the morning and you're set!
Seal your liquids. Place any bathroom liquids (shampoo, cologne, etc) ina large zip lock bag. That way if a baggage handler tosses your bags around you know that the goo and liquids wont be all over your belongings inside!
Dryer sheets for fresh clothes. Have you ever opened your suitcase and though, "what is that smell?" By keeping a dryer sheet in your luggage it eliminates the stale-suitcase smell and helps eliminate that jet-fuel smell if yous bag went under the plane.
Pack jewelry in Press n Seal. Don't want tangled bracelets and necklaces? Buy Glad Press n Seal. Place your jewelry on the "sticky side" and then place another piece (sticky side down) on top. It seals and prevents tangles.
Use SeatGURU. This website will show you exactly which plane type you'll be flying on and the seating layout. Hover over the seats and you can get the scoop on things like leg room, ability to recline, missing window, chargers, etc. Past passengers can leave their feedback as well.
Sanitary Money. Get ahold of a sanitary napkin wrapper. Put your credit cards and money in it, then tape it closed again. No one will steal that from you :)