One of the most important elements in traveling is absorbing another culture and respecting that culture in order to fully experience a place. A big piece of that respect is wearing what is culturally appropriate for said region or site.
Here are a few tips when packing and what your daily outfit should include when you're traveling in a new place abroad.
Light layers in a colder climate/Scarf or light jacket in warm climates
Nothing is fun or comfortable if you are too hot or too cold. Light layers allow you to be warm and still move effortlessly, while a scarf or light jacket can give you coverage from the hot sun or serve as a wrap around your head or shoulders to enter into a temple or mosque.
Close-toed shoes always
Unless you are on a beach, or at a pool, close-toed shoes should always be the staple. Do not underestimate the dangers of stubbing your toe, having your foot stepped on or stepping in something questionable.
Make your wardrobe work for you
Pockets, rain resistant jackets, convertible pants -- you do what you gotta do to avoid traveling around with three luggages and a carry-on that could fit a toddler. Avoid sacrificing versatility for fashion. Pack things you can dress up with accessories and clothing pieces that have pockets to hold the bare necessities.
Invest in their fashion
There is nothing I love more than getting a compliment on something I'm wearing and knowing exactly where it came from and who made it or having some great story about running through the rain to get to the market to buy these pair of shoes that I fell in love with the day before.
The rule of thumb that I suggest is lay out everything you want to pack, and then take out half to that, and then look at what you have left, and take out half again. At that point, you have the most necessary pieces left and that's all you should pack.