Congratulations and welcome to consulting.

I'll rattle off a few thoughts (some may have already been mentioned so if I repeat one, consider it for emphasis):
- Get luggage that is well designed and durable (I'm a fan of Briggs & Riley personally)
- Get quality, comfortable clothing. Quantity does you little good when you're hundreds of miles away from your closet.
- Related to the point above, look into wrinkle free shirts. Recent offerings are actually quite nice and should save you some ironing time.
- Move all of your bills and banking online.
- Per someone else's comment, get a credit card you'll use solely for business. Give some good thought as to whether you want to make it an affinity card that earns you miles or points. Considering how much you'll likely be charging, an annual fee may be worth it.
- Have your dry cleaner get your clothes to you folded ("in a box") rather than on a hanger. They're easier to pack and won't get as wrinkled by the trip.
- Pack so you don't have to check bags. Some people don't mind the wait, but it gets old quickly if you travel a lot.
- Travel with workout clothes. Eating out frequently + sitting all day + working late hours = a body that needs more exercise.
- Travel with a small alarm clock of your own. Don't depend on a hotel alarm clock or the wake up call.
- Learn your company's travel benefits and take advantage of them (but don't abuse them).