Tight Clothes
No matter how fashionable you intend to be, try to ensure you refrain from wearing tight clothing while on an airplane. This is because those tight clothes can restrict blood flow in the already confined space of an airplane seat, which can lead to risks of deep vein thrombosis, aside the prevalent discomfort you'll feel wearing the tight clothes. It is best to stick with wearing loose-fitting, natural and breathable fabrics when you intend to travel by air.
Dirty Clothes
This might seem obvious but you'll be surprised at how many people don less than clean items of clothing on their bodies, throw on perfume or cologne so the clothes pass the 'sniff test' and then head off to the airport. However, they fail to realize that odours are intensified in an airplane, because many passengers are cramped in close quarters and stale air is recycled throughout the cabin for the duration of the flight. It is therefore important to reserve clean outfits for plane rides and go easy on perfumes or colognes.
Complicated Outfits
A jumpsuit is a perfect example of a complicated outfit. It's probably not best to wear outfits that will make going to the bathroom in the plane a herculean task, or that will make sitting down for extended periods (which is basically all you do on planes) extremely difficult.
Pajamas or Other House Wares
The fact that you are advised to wear comfortable clothing when in an airplane, doesn't mean you should over do it and dress inappropriately all together, you're still going out in public after all.
Check the Airline's Dress Code
Simply check the airlines dress code to avoid being turned away for wearing clothing items that are non-compliant. Some airlines don't allow passengers to wear baggy or oversized clothing, mainly because those clothing items stir up the suspicion of airline personnel, as they will think you're hiding something in all that clothing. Some airlines do allow such baggy clothing, but you might have a tough time at security checkpoints because of how meticulous the security personnel is likely going to be during your security check.
