Traveling can consist of long days and nights, hours on end in airports and planes, and being unable to shower or freshen up. Being sweaty and in the same clothes for days can give you an icky feeling. It's best to pack a few extra things in your carry-on to prevent this feeling. Therefore, always pack extra undergarments like underwear, socks, and socks. Another outfit to change into upon landing is also a great idea.
Don't forget small travel-sized deodorants, toothpaste, and perfumes to help you feel revitalized after a long travel day. It may not be the same as a proper shower, but given the situation, it's as good as it can get.