Here are some "insider" travel tips from Chris J. who works for a major airline.
Call reservations to confirm your flight 24 hrs before a domestic flight and 72 hrs before an international flight for both the outbound flight and the return flight.
Check in online even if you do not have access to a printer. That way if there is traffic, or an accident, or you're just running late, you will be checked in even if the gate has restricted the flight check in process. Chances are you will still be able to make the flight.
If you are traveling with a pet, make sure you check the airline's website for the carry on dimensions of the pet carrier. The carrier must fit under the seat and cannot be placed on a seat or in the aisle.
If you buy a ticket through a discount travel agency, be sure to check the policies of the airline you're flying on by going to that airline's website. Often the discount agency's policy or information does not apply or is different than the airline's policy!
If you want to keep your suitcase looking new, buy a plastic cover to fit over the suitcase. Then the cover will get beat up instead of your suitcase.
Put your name on the inside and outside of your suitcase along with your itinerary. If the outside tag comes off, the inside tag will identify whose bag it is and where to send it.

SOME NEW TIPS:

Hangups!
I go to the 99 cent store a buy a dozen plastic hangers. Pack them with or without hanging clothing on them. When I get to my destination, where they NEVER have enough hangers, I'm set. And at the end of the trip I just leave them.

Good Will.
I also take some clothing that is still presentable, but may have some wear at the bottom of the trousers or items that I haven't worn for a while and just leave them at the last few stops. The suitcase just get lighter.

Crime with no punishment.
I tried this last time and not sure it worked since I've never had my pocket picked or anything stolen out of my day bag. I carry two small billfolds in my front pockets. This time I tried taking a napkin and stuffing it on top of my main billfold. Thought it might confuse or deter anyone trying to reach in there.
Some More Tips:

YOUR PASSPORT:
Make sure your passport is valid for a reasonability long period. Some countries require six months validity.
Hey you might break the bank at Monte Carlo and never come home!!!


Don't leave home without it!​
For a new or renewal passport you'll need two new 2 x 2 inch photos of your head against a white or off-white background. The Department of State's web site includes listings of post offices where you can get passport applications or renewals and blank passport forms.
Try not to apply during the busy months of May and June, however you can (for an additional cost) expedite your passport request.
And don't forget to take it with you!!!

PHOTOCOPIES
Make two photocopies of your passport, credit cards and other important documents. Leave one with a friend or family member and keep the other with you, but away from the real passport, credit cards, etc. If the items are stolen, this will expedite renewal.

TRAVEL AGENTS
If you have a good one you know they are worth it. Travel agents work for commissions paid by the airlines, hotels and cruise companies. But often the commission-oriented agents (and it's not a big commission) won't spend the time to find you the lowest fare or the best flight.
Recently the airlines have lowered the meager commission even more and some travel agents are charging fees. Look for travel agents that have completed the Certified Travel Counselor's Training (CTC), Certified Travel Associate (CTA), and/or belong the American Society of Travel Agents (ASTA) ((not the dog in The Thin Man)).
Ask them if they have been to the destination you are considering and if they will work to get you the lowest fare.
Now with the advent of the Internet it seems that checking the flights yourself and, armed with the lowest fares calling the airline, hotel, etc. directly, may work better.
Even if you are using a travel agent, I'd research these fares yourself just as a double check.

CREDIT CARDS
Take only the credit cards you're sure you will use. Carrying less cards, you'll notice if one is missing sooner. Keep the phone number of the credit card companies with your photocopies of the credit card numbers.
When traveling with your spouse, make sure you take different credit cards. If they are in the same name, and get lost you won't have to cancel both cards.
ATMs are usually the best way to get cash in a foreign country. Even with the surcharge for using a different bank's ATM, the net rate is the best or close to the best you can get.
Always get the largest amount of money you are likely to need at one time; this reduces the effective cost of any commission or service charge.

TRAVELER'S CHECKS
Traveler's checks are still great protection against loss or theft, but just about every place takes credit cards now and there are ATMs on every corner in the world.
Credit cards do charge interest and you'll want to make certain that your ATM and your pin work where you're going. Often with credit cards you'll end up with a better rate of exchange than if you would have cashed your checks in a bank.
If you decide to use Traveler's Checks, see if your bank, credit union or Auto Club sells them with no fee. Dollars are still the best bet for traveler's checks.
But, a selection of denominations makes sense. Choose large check denominations for long visits in one country or big expenditures and small denominations for ease of cashing or short stays.

MONEY CHANGING
Money is made by charging fees and also on the rate of exchange. Places with good rates often have high fees and places with low or no fees have poor rates.
Good money changing establishments show both their buying and selling rates. Places showing only one rate are hiding the fact that it is a rate not in your favor!
The fees are usually on each transaction, so if you find a place with a good rate, go ahead and get the cash you think you'll need all at once.
Take time to figure out the money. It will save you the embarrassment of being short changed or being treated like a child with his hand of change out for the store clerk to pick out the coins.
Don't change money in the U.S. before you leave. The rates are poor, and there is always an exchange booth in the passport area of the foreign country with better rates than at home.
In most cases, the best exchange rates come from using your credit card for purchases, but check with your credit card company most charge a fee for use outside the USA!!ATMs are usually the best way to get cash in a foreign country.
Even with the surcharge for using a different bank's ATM, the net rate is the best or close to the best you can get. Always get the largest amount of money you are likely to need at one time; this reduces the effective cost of any commission or service charge.

DUTY FREE SHOPPING
In 1947 80% of transatlantic aircraft stopped to refuel in Ireland, restaurant manager Brendan O-Regan opened a gift counter at Shannon a new free-trade airport in County Claire. Duty free shops are a world wide industry now with over $27 Billion in sales.
The business was built on tobacco and liquor sales since the elimination of taxes on these items (to be consumed outside the country of purchase) can be 8 to 30%.
Today the best savings are still on tobacco and liquor (cheapest in Asia).
Savings on other items is minimal. But there is an advantage of buying items not found at home.
Always check the limits on duty free items with Customs and Border Protection (https://www.cbp.gov/)

STRETCH YOURSELF
Blood clots and Travel.
Blood clots can sometimes form in your legs during air travel and even long car trips because you are immobile for long periods of time, often sitting in cramped spaces with little leg room.
Sitting still for extended periods of time can affect blood circulation and lead to the development of blood clots.
Airplane flights of four hours or more may be a risk factor for deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT and PE are serious complications of blood clots that may be fatal in some cases.
DVT and PE can be prevented and treated in many cases, and there are things you can do on long flights to reduce your risk. Even people with a history of blood clots can enjoy airplane travel.
During the flight
During the flight, you'll want to move around as much as possible and stay hydrated. Walk up and down the aisle for a few minutes every hour as permitted. If there's a lot of turbulence or it's otherwise unsafe to walk up and down the aisles, there are exercises you can do in your seat to help keep your blood flowing:
• Slide your feet back and forth along the floor to help stretch out your thigh muscles.
• Alternate pushing your heels and toes into the ground. This helps flex the calf muscles.
• Alternate curling and spreading your toes to improve circulation.
• You can also bring a tennis or lacrosse ball on board with you to use to massage your leg muscles. Gently push the ball into your thigh and roll it up and down your leg. Alternatively, you can place the ball under your leg and move your leg over the ball to massage the muscles.
• Avoid crossing your legs, which can reduce blood circulation.
• Wear loose, non-constricting clothing.
• Wear compression socks. Compression socks stimulate circulation and prevent blood from pooling.
And these exercises:


NO PROBLEMS
Some of the best ways to avoid delays and flight cancellations is to take the first flight of the day. If that's not possible then avoid the peak hours between 8 and 9:30 a.m. and 4 and 7 p.m. Fly in the middle of the week if possible (Tuesday through Thursday).
If a peak-hour flight is unavoidable plan the route through major airports (more options just in case your flight gets cancelled) and, of course!, fly non-stop when possible.
Bring a list of alternative flights to your destination along with the airline's customer service number. If there is a problem it may be faster and more efficient to make a reservation on the phone than with the gate agent.