My approach is to find a pair of pants (or anything else) that feels and looks good, and then to buy a pair in two or three colours, e.g. black, brown, navy. Same with shirts. Then mix and match. For travel, something stretchy is most comfortable. This time of year I usually wear casual pants, a T shirt and sweatshirt over top (+parka, gloves, boots!). I like cotton socks with no band around the ankle. Tabi is my favourite brand, but might not be available in the US. I often include a scarf, both for warmth and to vary outfits. Another useful item is a dressy indoor jacket. Just put it over a black top and pants and you're ready to party!
If my trip is more than 48 hours I will check in a suitcase. I fold my clothes and wrap them in the plastic sleeves that the drycleaners give you. I put business clothes on hangers and hang them up immediately I get there, and the wrinkles fall out overnight; often I don't even have to iron them in the morning. Generally I avoid "high maintenance" clothes even for business.
I have a large tote bag that I got at a conference and it is wonderful because it has a zipper and can take all the carry on you could possibly need. For long trips I always toss an extra pair of underpants and socks in the tote bag!!! If you use any medications, make sure they are in there too.
Khan, I know you hate shopping, and one idea that you might consider is to call one of the department stores before you go to see if they have a personal shopper. I did this once. Just gave her my size and preferences. When I arrived she had a rack of clothes ready for me to try on in a spacious private dressing room. When I chose what I wanted, she was able to get me everything on sale. It was a breeze: LBYM with panache and style!