I have grown up in America. When I travel I tend to pack like an American which means I bring way more stuff than I really need. Since the 9/11 and new security precautions things are a bit more difficult.
When packing for a trip outside the USA aside from probably encountering electrical issues and the need for getting the proper converters. That is something that can't be avoided but can be planned wisely. I've said this before before you go out and buy one of those converters check to see if your power supply is rated for dual voltage. If it is then all you need is the appropriate adapter plug.
Now that most airlines charge for the extra suitcase or weight then there are ways of getting around those expenses sort of. On my last trip I decided that I wouldn't pack any liquid items. I didn't take anything buy my razor and toothbrush and tooth paste. I didn't bring my usual shaving lather. Soap, shampoo, rinse and those items can be purchased at your destination if you are traveling to a well populated area.
Depending on the time of year that you are going to travel you can choose what you'll need. If you are traveling in the summer then you can take a pair of sandals or footwear that doesn't require socks.
I tend not to pack any more shirts than I need. If I'm traveling and it takes me the flight over then I pack two extra shirts aside from the one I'm wearing. I make sure that they are old shirts, ones I'm not interested in keeping. I know I'm going to buy shirts as souvenirs so why pack extra? I'll leave the old ones and I won't be adding any extra weight to my suitcase on my return home.