Carrying your business cards is always a good idea. It helps you network better and also acts as a reminder for the person you might have interacted with. As a bonus it also makes you look super professional.
Bad breath is the last first impression you want to create to a new likely associate. Have one when ever your mouth feels dry or simply to boost your confidence
Constant travelling and shaking hands is a part of the package when you are a businessman. Make these your best friend to avoid catching a cold or any other transferable allergies.
A Pen and Pad
Nothing like writing down pointers and keywords during a conference or meeting. Always keep a notepad and pen ready to make sure you never miss out on the important stuff.
Have to make an important call but your phone is always running on low battery. They havent created power banks just for show. Invest in one that is compatible to your usage and always be rechabale for important calls.
Carry your own laptop or tablet instead of depending on your visiting company to provide you with one. Not only will you not waste time familiarizing your self with a new peice of technology, you will know exactly where all your documents are stored.
A USB flash drive
Always, always carry a USB with you on your travels. It lets you back up all your important data and acts as a life saver in cases of emergencies. You dont want to get fired over something as silly as not carrying a back-up of your work.
A multi charger
A multi-charger is a must for any business traveller. You save space and time by being able to charge all your devices at once.
Small First Aid Kit
It is important to have a first aid kit with essentials like band-aids, pain-relievers, cough syrups and necessary vitamins before setting out to travel.
Pack only the essential care items
Pack only what you know wont be available at the hotel. Most hotels provide all the essentials. This saves a ton of space for other more important things.