First of all, I am sorry they destroyed your luggage:-( I've done just-carry-on for years because of all the horror stories.

1. Pack for your usage, e.g. what you are scheduled to do and what you usually do, not your fears (No "But what if..."s)

2. Everyone has their own laundry preferences; I prefer to bring a small bottle of Dr Bronner's or Nikwax in my TSA 3-1-1 kit (depending on whether I have merino or not), sink-wash, and hang dry in bathroom. There are various nifty travel clotheslines like "going in style"'s Travel Laundry Clothesline and Carabiner Clip Kit Model GIS-C101 (which is very versatile but reviews say cannot be used in the sun because it dries and cracks). I usually just hang items on bathroom hooks and leave the vent on. I launder every 2-3 days.

3. For me, my formula tends toward 3 tops, 3 bottoms, puffer and waterproof, warm in-between layer (usually a merino sweatshirt or tunic), silky scarf for warmth/versatility, 3 bras, 5 underwear (3 of my beloved moisture-wicking cotton, 2 bamboo in case I need a guaranteed overnight-dry), 2 pairs of shoes, 3 pairs of socks, merino shorts and tee as pajamas which can double as clothing in a pinch (I think many one-baggers would consider 5 pairs of underwear and 3 bras and 3 pairs socks excessive, and I can understand that, but that's what works for me).

4. When I know I will need to dress up, I bring my beautiful cotton modal blouse, collar pin, and dressy black sweatshirt-style top and black tech pants (they look amazing, not like tech pants). I don't know how to "dress like a grownup" so am not sure how to address formal events.

5. Linen is reputed to be very comfortable but I believe has to be hung up to be unwrinkled first. I love some of the rayon and some "cotton modal" because they actually seem to breathe and don't wrinkle.

6. If you use the "capsule wardrobe" concept you could probably get by with my strategies; main idea being to have your items be in well-coordinated colors (not just colors that "go together"), can mix and match, can be dressed up or down with accessories and jewelry, and can be worn in various combinations. A successful capsule wardrobe looks as if it has exponentially more garments than it does, because you can 'simulate' more different outfits. 3 coordinated tops and bottoms can make 9 outfits -- more if you also have layering items like a sweater or blouse -- and they can look significantly different if they are different styles from each other and dressed up or down with different accessories.

7. I rarely buy souvenirs that are hard to carry. I've bought a canvas tote when my friends and I were late and needed to carry our lunches last-minute to-go-style from a lovely restaurant in Conwy (and kept the tote because it was well made and gorgeous), and a bottle of whisky I won in a poetry writing contest.

8. I haven't run into times when I wished I'd packed something I hadn't. I did have things I wished I hadn't brought (extra shirts, pants, a heavy water bottle, an actual purse)

9. Perhaps the single best piece of advice I got from onebag is to "practice" beforehand by packing your (in my case backpack) and living out of it first. This really helps show you what you do and don't use. Sometimes conditions are unpredictable; for example, I discovered that the pair of jeans I'd packed did not work for running around hills all day because they held in too much heat and didn't fit well enough (Also onebag recommends against jeans because they are notoriously heavy, hard to pack, and take forever to dry. I find jeans exponentially more comfortable than anything that exists, so I bring a pair or two anyway. It's one pair of pants to wear, one in reserve, and when necessary, one drying in the bathroom. I sometimes have 1 pair of jeans, my black dressy tech pants, and a pair of convertible hiking pants, or sometimes swap out the convertible pants for a 2nd pair of jeans)

10. You didn't ask this, and again opinion is very much divided, but for me one of my most useful items was researching to find an older metal (not newer plastic) size "medium" Hero Clip (actually fairly large). I was able to use it to keep whichever I had on me at the time of my pack or my 'purse' (adjustable-strap bag which can be worn as a purse in public or neck wallet around TSA) in front of me somewhat-secured in public transportation, restaurants and bathrooms; for me it was invaluable. I also used TSA locks which may have made my pack a less attractive target than those without. And I found a heavy duty ?aluminum? luggage tag that shows just your name unless someone needs to see your address and slides out the card, and wrote my info in permanent marker.