My bag of choice is the Rick Steves Rolling Carry-on. I change my personal bag from time to time, but usually, it's a Vera Bradley Tote with zipper.
My packing philosophy is pretty simple. For clothes, I follow a color-palette for the trip and make sure that every piece fits within that palette. Each piece has be able to worn at least twice - either with different accessories/top/bottom/whatever - or out it goes. I bring multiple scarves (2 or 3) and I mix it up by changing a bit of jewelry. So, if I wore a certain top with a scarf, the next time I wear it, I'll pair it with jewelry. For those of you ladies saying you'll get bored, I get what you're saying, but I've not yet found it to be a problem. In London, when I got bored, I bought another scarf - lightweight and easily packable. Pants, I'll admit, are a bit harder because they take up more room/weight. I don't care if they're heavy, I have to have jeans. I usually take 2 pants for a week, 3 for two weeks. After considerable trial and error, I've invested in quick-dry undies. You don't really realize just how much room underwear takes up!! It's crazy! And I found that my regular cotton undies just don't dry quick enough in a hotel room. So, I take 4 quick dry pairs and wash one each night. Takes 5 minutes and saves a lot of space. I'll admit that shoes are a problem for me - not because I feel the need to take a thousand pairs, but I do need to take 2 and that's hard with carry-on only! In colder weather, where shoes are heavier and bulkier, it can be really frustrating! On a recent trip, I took only 1 pair of booties and I really regretted it. I wanted that extra pair of flats when my feed needed a break and the weather warmed up. I still don't have a good answer for that one...For toiletries, I purchased a set of small tubes and jars from Amazon for $20 and I use them whenever I travel. It's really been a lifesaver and has allowed me to cut my toiletry case (and my 311 bag) way back! For makeup, I don't take anything fancy. I do take a full face of makeup, but no extra fancy eyeshadows or extra brushes. I take only what I need for "an everyday face". Most importantly, I have a toiletry case that is thin and packs flat - it takes up very little space.
My challenge is with non-clothing related items that go in my personal bag. I've stopped carrying books in favor of my iPad (with e-books) and I've had to learn to leave the magazines/sewing projects/guidebooks at home. I used to need them to entertain myself on the plane, but these days, with in-flight entertainment and my iPad with books, it really is enough. My luxury item is my DSLR. Not only is it big, but heavy, too. And of course, you have to take the charger. I leave the fancy lenses, but still it takes up more room than I'd like. I also take a crossbody purse that folds up flat and can be used as my day bag when we arrive. The goal with my personal bag is to keep it as empty as possible so that I can use it for my souvenirs on the way back, Ultimately, I'd love being able to make my personal bag and crossbody the same bag, but I'm not there yet.
Truthfully, I think that almost everyone is capable of packing the Rick Steves way, but I think many people genuinely don't want/aren't willing to deal with the hassle...I don't mean that in a nasty way. It takes years to really master how to pack that way...I'm pretty proud of how well I do, but I'm still learning! For a lot of people, it takes the joy out of the process to have to plan that minutely. While I personally think that level of planning makes for a smoother trip, not everyone feels it's worth it. My mother is a perfect example. She absolutely refuses to carry-on. She would rather have the luxury of taking what she wants and she'll willing to deal with whatever frustrations she encounters to have what she wants. I don't agree with her, but I can't really argue her logic.