I am a very light packer. I travel fairly frequently so I've invested in clothing that works especially well for travel; light weight, quick drying OR merino wool which is naturally moisture wicking and doesn't need to be washed as often.
No matter how long I am gone for, I usually pack the same:
3 tops
3 bottoms (mix of skirts and pants)
*The 3 tops/3 bottoms should be able to mix and match to create up to 9 separate "outfits"*
underwear and socks as needed
3 pairs of shoes; running shoes, "every day flats" (the specific type varies based on where I am going) and flip flops
One workout/running outfit
light weight pajamas, one set
bathing suit and cover up (unless I am going somewhere it won't be needed)
Jacket (small/packable)
rain jacket (packable)
toiletries; always in small bottles, and greatly pared down. I don't bring much makeup. I take advantage of any hotel toiletries I can, etc.
A portable clothesline, since I wash clothes in the sink and hang them to dry at night.
https://www.amazon.com/gp/product/B01LZYLO2A/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
I can fit all of my stuff into a carry on size bag, usually with room to spare. I went to London for 6 days with my two sons (12 and 14) last week for spring break. We packed everything into 2 carry on bags (they each carried one) and a 20L backpack (I carried), with room to spare.