Packing for a Work Trip

When I travel for work, it's usually with my boss- who hates to waste time waiting for checked luggage to come off the plane. For that reason, I've become adept at fitting my laptop, flat iron, clothes, and toiletries into only a large purse and a small carry on. I've managed to fit outfits for two days, plus workout clothes and shoes into the bags shown here when necessary, but my most recent trip was less complicated. I needed a set of work clothes, plus clothes to go out to dinner in Houston at a local restaurant called Cyclone Anaya's (which was really good) with my boss, our colleague, and his wife.
I though it would be fun to document what I wore, because this is pretty typical for a work trip. In the summer in Houston, I have to consider two factors- that I will be miserably hot the second I set foot outside, and that I will be freezing indoors. So the business clothes I wore on the plane and to work on day one were charcoal dress pants, black flats, a black tank top and a pull over light weight sweater. (Excuse my death glare, I tend to look fairly evil when I'm not smiling- really I'm just concentrating. Also, my hair is usually a lot nicer, but I have to get up really early during my work trips so I wash my hair the night before and just haphazardly flat iron it while chugging coffee the next morning.) For dinner that evening, I kept the tank top and topped it with a knit dress. I wore black flip flops (had the restaurant been dressier, I would have worn the flats instead and maybe packed a dressier dress), and brought along a khaki jacket. (Does the jacket look familiar :), Amanda?)
Finally, for work the next day, I wore the same charcoal pants and black flats, topped with a short sleeved sweater. I also wore the khaki jacket most of the day because it was cold inside the office.
As for where I put everything- my laptop, flat iron, clothes (which I rolled), and flip flops fit easily into my carry on. My wallet, toiletries, a notepad, and a book fit into my red purse. However, on trips when I bring workout clothes, I usually keep my laptop in my purse to make room for my running shoes.
These outfits actually represent pretty typical work clothes for me. I tend to live in black, charcoal, and brown dress pants, topped with dressy sweater or knit shirts (button downs don't fit me very well.) I tend to wear small pieces of jewelry as well because I think big bright accessories overwhelm me. And I almost always wear flats, even though I sit at a desk most of the day and could probably wear heels pretty comfortably.
What are you work staples? How do you pack for a trip?