What to pack when you are traveling on a plane depends on your airline of choice and how much luggage allowance you got. However, there are some safe rules that you can follow.
The first question you have to ask your self is where you will be going. If you are traveling to a place with fine restaurants and you have a lot of reservations, count how many “fine” outfits you will need, split that number in half and take that many. You can do double duty on your fine outfits by wearing them twice (unless you are a celebrity who is being photographed every time you step out, or you spill food on your clothes every time you eat).
In regards to the rest of your clothes, don’t pack a bunch of stuff that you don’t normally wear just because you run into them while raiding your closet. You will not take your work clothes of course, but do take things that you currently wear on your weekend.
Also, if you are not checking a bag there is a limit of how many ml you can carry on board for food and liquid items. Even a cream cheese maybe thrown away, if it weights more grams than it should. So, don't buy it if you can't take it on board.
When it comes to shoes, a lot of people usually get it wrong. Because nobody wants to bring the comfortable flats which are not so appealing and instead they usually take the nicest heels. Big mistake when you are on holiday and you have to do a lot of walking.