With this list I have been away for as short a time period as a week and as long as a month.
Business travel is not construction work so the suits, if properly maintained, need only be cleaned at the end of the trip. To extend the time between cleanings wear a suit for one day, hang it up inside out to air and let moisture dry, then next day use a soft brush to brush the inside of the coat and pants, then hang them correctly and lightly steam and brush the outside. A travel steamer can be purchased for as little $20 and is not larger than a hair dryer.
The shirts will have to be laundered at least weekly and maybe occasionally more frequently if the weather is hot or you need to change shirts often.
The 12 ties will give you variety in the wardrobe. A suit is a suit and not many will notice it is the same one you wore previously, but they will notice the tie.
Shoes to take with you should include a black pair if you have a black suit, brown pair for almost all others, and a casual pair of loafers.
The sport coat and jeans, with the loafers, is your casual attire to wear on the travel and after your professional day is finished. You still look professional but more relaxed.
Sneakers, shorts, swimwear and exercise clothing is up to the individual. These are items that are also useful when hanging around your hotel room. I’d rather sit around and watch TV or do reports on my notebook in my hotel room wearing these than sitting in a suit. I don’t care if food is spilled on them, or they become wrinkled from lying on the bed watching the television. They are also easy to wash in a sink or bathtub and hung over the shower curtain rod to dry while you work in the daytime. The same goes for socks and underwear.
I use this list always when packing for a trip.
3 to 5 suits
3 pair shoes
Sport coat & jeans to travel in.
Casual clothes such as gym wear, shorts & t-shirts.