Read your flight details carefully. There are many stories of people who fail to catch their flights!  Interchanging boarding time with estimated time of departure, when the ticket reflects military time sometimes its quite confusing. My point is read the ticket carefully. Also the conditions that goes with it, like your allowable weight limit. And most airports now don't allow liquids, gels and aerosols as hand-carry items. Study and follow the instructions to avoid further hassle at the airport. 

Arrive ahead of schedule. If it says you should be there three hours before, be there on time or earlier.  This will save you a lot of queuing.  It will give you plenty of time to relax and enjoy the scenes...at the airport. Then you can enjoy shopping or browsing items at the duty free shop.  Have a coffee and cookie as you wait for your flight.  You may send your ciao! see you soon! via your cellphone which is not yet turned off. Start spreading the news!

Think and rethink what's in your luggage. For those migrating or staying long term pack everything you can! For business or holiday, trips which are short pack only the essentials. Mix and match your clothes, better bring one pair of shoes the other pair you are wearing already. If you will bring your own toiletries put them in small containers which is only for 3-4 days use. Think and rethink what's in your luggage the best is to have one check-in and one hand carry.  Better, if possible no check-in.  Thats no more waiting in the carousel, just get your bags from the overhead bin and go!

Choose an aisle seat.  I like front row and aisle seats.  Front row is usually spacious. Aisle seat its easy to get in and out of your chair.  Exit rows are also good you have more leg-room, but now it usually has a premium price.  The window seat is good for the view.  Better choose your seat online where you will be comfortable.

Dress appropriately.  International flights and airports have cold temperature.  Bring in something to keep you warm like a jacket, sweater, shawl.  Also check the weather on the city where you will arrive is it rainy, winter, summer or fall. Also check the culture of the city where you will arrive, certain clothing are not appropriate with certain culture.  As to not alarm the immigration officers, wear something that will not demand attention or will make you look suspicious. 

Keep it handy.  Always always bring your own pen, in traveling there are forms to be filled and usually no pens. Keep your passport and airline ticket always within your reach.  Better if you have an organizer where you put all your travel documents in that one small jacket. Keep cash handy.

Enjoy the journey.  Several hours in plane is boring.  But try to kill the time by reading that magazine in front of you, bring your own book for reading or activity, handheld video games, write a poem or an article, write anything, stretch, eat, better sleep if you can. 

Arrive fresh.  When you are near your destination, refresh! Put a little make-up so you wont look dried-out, straighten your hair, so you wont look you just got out of bed.  Collect your things which was scattered in the floor, in your seat, and in the pocket in front of you. Ready that stylish shades to complete the look -- if its sunny outside you'll see from the window.  

Welcome aboard!