1. I bring an empty "Honest Tea" bottle on board. My favorite for taking water with me--has a wide neck. When they serve the beverages, I pour mine into my bottle, ice cubes and all. Then I can have it whenever and don't worry about knocking it over onto my lap. I don't get soda so going flat isn't a problem.
2. I have used a lot of different carry on bags, cheap and fancy. I don't mean the rolling bag with your clothes in, this is a smaller bag to carry the things you will use during the flight: reading material, electronics, snacks, neck pillows, etc. What I think works best is a smaller gym bag, maybe 18" long, barrel shaped. It is short enough to be shoved under the seat ahead of you and has a flat bottom and zips open fully so that you can find what you are looking for. Many have both hand and shoulder straps. Since it zips together completely, you don't need to put it in a bin to go through security. A lot of travel bags are taller with many compartments, and things disappear. You need to haul the thing up onto your lap to find those earphones or whatever it was you needed. Or they tip sideways under the seat and you can lose things on the floor. Anything bulky like a sandwich gets squeezed into one of the compartments. And I paid good money for this thing?
For a train or bus trip, a nice sturdy shopping bag can also do the trick.
3. Okay I have one more quick one: Make your car rental reservations a few weeks ahead or whenever. Don't prepay. Then about a week before, check again. You may be happy to find a cheaper rate. Get the new reservation and cancel the existing one. I just did this for a five day rental in California and saved $48. The final rental, with taxes and fees was less than $20 per day.
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