As my husband will tell you, I dither around a lot about packing. Since I want to travel light, I feel like I need to pack exactly the right things: clothes that will mix and match well, be appropriate for the weather, look nice, and dry quickly when laundered. It sounds difficult, and I dither, but in the end, it comes together.
A packing list is important. After some tropical trips where I arrive from the rainy and dark Pacific NW without sunglasses, I have learned. Make a packing list. Whether you use paper or an app like PackTheBag, make a list. List even things that seem obvious.
Here is the list I used on our recent trip to France. A photo of my packed bag is below.
Long sleeve top
Socks, shoes, underwear
1 zip-up black blazer
1 Smartwool sweater
7 pair socks
1 pair shoes
Misc: gum, Clif bars, iPad, toiletries, headphones, iPad charger, earplugs, sunglasses, hair clips, earrings, necklace, notebook, pen, train tickets etc., washcloth, guide book, passport, credit/debit cards, cash