Ideally if you're bouncing around Southeast Asia, you'll want to keep everything to a minimum. I did the entire three week trip through Vietnam and Thailand in just a carry-on, and it was completely doable. For a three week trip, we had to wash our clothes just once which was $40 at our hotel for the two of us, and we washed a few items like undergarments by hand. This was completely worth it, given that we had a total of 7 internal flights, where luggage would be $20 a bag to check.
Hot weather, humid conditions, and a variety of destinations meant packing extremely smart. I packed, re-packed, and re-packed again and again. I made sure I had exactly what I needed for the trip, yet still felt like I could feel fashionable for the trip.
Here's what to pack for a Southeast Asia trip:
+ 3 bottoms (casual soft shorts, denim shorts, and linen shorts)
+ 1 Loose pants for walking during the day (like these black ones, or these fun colorful prints)
+ 3 loose t-shirts (like this basic one, or this deep-v tee)
+ 4 tank tops (like this basic one)
+ 3 day dresses (like this adorable long dress, this one pictured below, or this easy day dress)
+ 2 skirts (a long one for temples, and a day skirt)
+ 2 rompers (love this one and this one)
+ 3 swimsuits (a basic black one, one good for snorkeling, and one for by the pool)
+ Trip insurance (see why in this post)
+ Sunscreen for your face & body
+ Insect repellant
+ Bandaid kit
+ Lip balm
+ Polarized sunglasses
+ A dry/wet bag for in between travels
+ A good hat like this one
+ Day backpack like this one I have or purse that easily packs
Notes: All of this can fit if the material is light and not thick — wear your biggest items while traveling, and roll the rest to fit into a carry-on.