I alternate between one 28" checked suitcase and a laptop bag or a carry-on and my laptop bag. My biggest hurdle in carry-on only, is the liquid and gel limitations. It's not enough to get allowable travel sizes of all your hair products, toothpaste, deodorant, lotions, etc., but they all have to fit in a quart size bag. In regards to clothing, I find that I invariably use only a quarter of the items I pack. I tend to launder dirty items as I don't like the thought of carrying them around during my usual frequent stops in different cities. I find UNIQLO's AIRism undershirts a godsend in hot temperatures as they absorb perspiration and odor, keeping your shirt fresher for more than just a day. A quick wash of the AIRism daily in a sink with whatever soap or detergent you may have at hand, and they dry within an hour or two. If I need to wear a suit or jacket, and don't wear it on my flight or in between stops, I have learned a method of folding it inside out that limits the amount of creasing while it resides in my suitcase. I also coordinate clothing so that I can match any given item with all the others. One trip it will be shades of blue, another black, another tan, etc. Same for shoes. They must match my attire and I always bring one extra pair along with some flip flops for any pool time. My wife was a fashionista, and it rubbed off on me, for better or for worse.
For electronics, I bring location specific plugs, adapters, my laptop, phone, the appropriate chargers, noise canceling earbuds and a power bank. I also bring a special duffle bag that folds into a flat 8'X10' packet, just in case I decide to do some last minute shopping on my return.