The longest trip I've been on is 3 weeks, but I think the concepts are still the same. Meaning, you basically pack for a week or so and plan to do laundry.
I typically prefer to travel with carry on luggage sizes, even when I ship through a bag.
My questions would be:
Are you expecting to travel to varied climates?
Will you want clothes for a variety of experiences (such as dressy clothes, swimming, hiking, etc)?
I typically take 3 dresses that have a very simple line and fabric, that can be dressed up or down. I use them for a nightgown, beach cover-up and dress. Basically a dress like this (I use this brand):
https://smile.amazon.com/Jostar-Sle...hort/dp/B008NEDUCU?ref_=ast_sto_dp&th=1&psc=1
I have one in solid black, one more floral and one geometric. They don't wrinkly, was easy and are versatile. They wash easy in the sink.
I bring this jacket:
https://smile.amazon.com/dp/B089GDNS8S?psc=1&ref=ppx_yo2_dt_b_product_details
I wear it with jeans, and also to dress up the dresses above.
I also bring along a pair of bike shorts. I can wear them under the dresses or use for hiking with a tee.
I need very supportive shoes for every day use. I wear a pair of black sneakers and pack a supportive sandal that can be used for a lot of walking as well. Then I pack a pair of croc flats.....I wear with the dresses for dinner, with nice pants as well as at the beach or pool.
My preferred color schemes tend to be navy + taupe for bottoms or navy + black. Then I added in varied tops that match, and use stripes, solid colors and floral, with varied styles. I usually bring a pair of jeggings rather than jeans because they pack lighter and dry faster.
If you are doing wash in your sink, after you wash, wring well and then roll in a towel. Then, the real secret is to walk on the towel! That really gets the water out and allows it to dry faster.
I often pack a cold weather kit when I'm not sure of the weather. It is includes a pair of magic gloves (the kind you get from Target for a buck or two), a cotton gaiter, a pashmina, a pair of sock liners, a cotton undershirt with a little lace and a pair of tights. This all fits in a gallon ziplock bag and it's pretty flat. If the weather is unexpectedly cold, I find these items really help, It gives me extra layers and with whatever jacket I have on that trip, my feet and hands can be warm, my neck is protected and I can use the pashmina as a scarf, or as a hood and scarf. And if it's not needed, you haven't wasted that much space.
I love this backpack:
https://smile.amazon.com/Hynes-Eagl...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
If you underpack it, it can even be an underseat bag on certain airlines.
"Lady light travel", she has some great ideas for packing light. (
https://ladylighttravel.com/) I also recommend the packing forums on Rick Steves website (
https://community.ricksteves.com/travel-forum/packing). I also like "Her Packing List" (
https://herpackinglist.com/). Googling "minimalistic packing" gets you some good sites.