With nearly every airline imposing a baggage fee nowadays, if you can get away with flying with just a carry-on, do it. Save your money for drinks with the boss. The key to an expertly packed bag is space optimization. Shoes (stuffed with socks or ties) and other heavy items like your dopp kit go on the bottom, in the ridges of your bag. Then fold and stack clothes, starting with your most casual pieces (jeans, gym clothes) and topping off with more refined pieces (suits, dress shirts). Fill in any gaps with rolled undershirts and underwear. As for what to bring here's a fail-safe list.
Water repellent wheeled case, $124 at Muji
* Optional: workout gear.