For air travel, you should strive to look nice on the plane, but should also try and avoid wearing your best looking clothes, unless you need to head directly to an important event after the flight. While at the airport and during the flight, countless things can and will happen to dirty your clothes. You may get dirty while carrying your luggage, get spilled on by fellow passengers, or even sit on something on an unclean seat on the plane. That said, you should still dress professionally. You never know who you will run onto while in the airport and always want to maintain a positive image. Additionally, airlines are more apt to let you into private lounges and upgrade you if you are dressed the part.
Also, consider purchasing a carry on garment bag. A quality garment bag will allow you to easily pack your clothes and keep them wrinkle free?all without having to go through the hassle and extra time of checking a bag. If you are brining along a sport coat or jacket, its recommended that you store it in the bag so it is protected.
Finally, if you are flying first class or hope to be upgraded, remember to dress nicely. Nothing is more embarrassing than looking like a slob in first class and getting shunned by other passengers. Looking the part will make you more inviting to fellow passengers in first class. These passengers may turn out to be future business partners or customers, so they are important to talk to.
When boarding the plane, ask the attendant to hang up your jacket for you
Wear your most comfortable dress shoes?sitting on the plane can be uncomfortable after a while
Make sure you fold your clothing and pack it so that it remains wrinkle free