- Odd jacket, slip-on shoes, shirt and trousers for travel days when there's no meeting before or after the flight
- Two suits for three days or three suits for up to five days
- One dress shirt for each day plus one white shirt for each evening event
- One necktie and pocket square for each day plus one for spare/evening
- Two pair dress shoes and belts or braces
- Underwear and socks for each day plus one spare set
- Sleep wear for each night
- One sweater or knit polo
Personally, I prefer to pack only gray suits for day wear, though I will substitute navy when there is an evening event. Gray simplifies my shirt and tie choices, and lets me stick to black shoes.
When there is black tie on the agenda, the aforementioned navy suit with a white shirt and a black bow tie makes a passable substitute without adding to the packing burden. Carrying the real thing is overkill unless a man is a speaker, honoree, or has a reasonable liklihood of a romantic evening.
The entire process should take no more than ten minutes.