(Author's note: I have not been paid by nor have I received any in-kind items from the following companies.)
This is assuming all of your clothes are washed and ready to pack. This does not include time spent taking clothes out of the dryer, etc.
This is how I pack for a week-long trip using a carry-on suitcase (yes, you read that correctly - carry-on suitcase. I don't check luggage anymore. Much quicker, and you know that you actually have your luggage when you get to your destination.)
1.I color-coordinate everything. I stick with a color scheme of up to 3 colors. Usually this is black and red. It's kind of like the Garanimals kid's clothing line - the tags matched up so you knew what went with what. (Do Garanimals still exist?) This does result in my having suspiciously similar outfits in my photos from China, Europe, etc....but really, who cares?
2. I pack items that don't wrinkle. Travelsmith has a line of non-wrinkling clothes. This is how non-wrinkling clothes save you time on packing: You can roll them up (length-wise) quickly without being concerned about wrinkles. This also saves you space in your suitcase.
3. I buy travel clothes that can easily be dressed up or down. One of my favorite kinds of shoes is a ballet flat. Like this. They go with pretty much everything.
4. I use SpaceBags. It creates much more room in your suitcase, and speeds up the packing process. No more trying to hold your suitcase together so you can zip it up.
5. I don't sweat the small stuff. If you forget something, there is a 99% chance you will find it wherever you are traveling to. If you forget your phone charger, go to the check-in desk at your hotel. There is a big box there of chargers people have left at the hotel. Chances are there's a charger that matches your phone.
6. My mantra is "remember your glasses/contacts, remember your meds". Everything else is pretty easily replaceable. Even if you do forget your meds, chances are that you can get them called in to a local pharmacy.
7. I pre-pack my toiletries. Remember, Ziploc bags are your friend. I have a bag of travel toiletries ready to go. I just put them in my carry-on. Remember, though, if you have any liquid items, keep them in a quart-sized Ziploc and put them in the outside pocket of your suitcase. This ensures easy retrieval when you go through airport security. If you are not sure if something is a liquid or not, put it in the liquid bag anyway. My experience has been that mascara does not count as a liquid at some airports, and it does in others. I have one-day contacts, and I even put them in the Ziploc, since there's a little bit of saline solution in each one. I also pack solid foundation instead of liquid foundation. I use MAC's Studio Stick, but alas, it has been discontinued. It was tough finding a comparable item, but it looks like Bobbi Brown makes a foundation stick.
8. This leads me to my next tip. I have two versions of my makeup. When I'm at home, I use liquid foundation. When I'm traveling, I use the MAC Studio Stick. (See the link above). It works the same way, and holds up pretty well if you are getting pictures taken or doing a studio interview under bright lights. One of my other favorites is Stila Convertible Eye Color. You have your eye liner, eye shadow, and a smudger all in one stick. Thank you, Jeannie Lobell. (She's the genius behind Stila.) I keep this in my travel makeup bag, and use another eye liner when I'm at home. It's super-easy to just toss my bag of travel makeup in my suitcase, and I know I'll have everything I need.
9. I cut and pasted a from the internet, put it in a checklist format (you can get a similar template here) and I laminated it. You can buy adhesive laminating sheets at any office supply store. I use a dry erase marker and check things off as I pack them. This is a quick and easy way to determine if you are missing something.
10. I print out any kind of booking confirmation (hotel, car, airplane, etc.), and maps I need, and I print out my itinerary. I then hole-punch them and put them in a presentation folder (the kind with a clear cover). I put everything in chronological order, with my itinerary as the first page. Easy access, and great since I am very visually-oriented. And even if you do have a Blackberry, iPhone, or GPS, it's always nice to carry a hard-copy as well.
Although some of the items listed can be pricey, they are totally worth the amount of time they save. Also, the more you travel, the easier it is to pack. I didn't learn this stuff just by going on one trip - it has been trial and error across many trips.