A lime green Samsonite duffel bag is what I use when I'm flying because I don't mind it getting a little banged up on the airport or in the overhead compartment. I also love the color.
For hand bag, I usually have a Samsonite or Targus backpack which houses my "real" handbag among other things. Most of the time it's either a small shoulder bag from Esprit or a medium one from Adax or Longchamp that's hiding in the backpack.
When I travel by land or sea and will be staying for less than 5 days, I usually have my Day Birger et Mikkelsen Gweneth tote or Tiger of Sweden Meya Weekender in tow. As I need to have a book, my tablet, snacks, water bottle, makeup etc. in my handbag, I go for a medium shoulder bag, many times it's my Longchamp Le Pliage Cuir, Mulberry Flight or Lumi Supermarket XL. As you can see, my perception of "medium size" is pretty different from most other people!
I never travel without some Longchamp Le Pliage nylon with me, too. I might have a Large LH tote and a Small SH folded up in my suitcase. I'm wanting an XL LH custom LP in my life as well, we'll see how much longer I can stop myself from ordering. Not much longer, I suspect. I'm weak.
I've also used a leather Legacy tote from last year as a carry on before. I love it, the vachetta leather is delicious.
