I travel a lot, and over the years I've slowly and painfully gotten the hang of this packing thing.
Here's what I do.
I lay out all my clothes as outfits, one for each day up to two weeks. Any trip longer than that and I acknowledge that I will have to do laundry.
If I have a few clothes, I wash them in the sink with shower gel or shampoo. A larger load requires using the bathtub and stomping (carefully), grape-smashing style.
I try to keep everything interchangable, in case I need to switch it up once I arrive.
I bring layers. A multi-layered combo of t-shirt with a long-sleeved top and a thin jacket topping it all off is surprisingly warm, has a lot more wearability and takes up less space than a single heavy sweater.
I always take a photo of everything before the final loading, in case the suitcase gets lost and I need to file a claim. It helps me remember what I packed, which isn't as easy to recall as you may think.
It took a while to get this trip's packing down, since I am gone for 5 weeks and in a veriety of differnt places - in cities, on a boat, in the outback. Flexibility is pretty important.
Diane von Furstenberg gives some packing tips in the latest Allure Insider's Guide.
I was reading it on the plane. She made me laugh.
If I followed her lead, I'd have to trade my quick-dry hiking pants for a black cocktail dress. I don't think 'boot if it's chilly' means hiking boots to her.
She's with me on the layering, and on the interchangability.
We diverge again on the notion that I may be invited to a fancy party, and need jewelry to formalize my outfit ... do pearls go with gore tex?