Remember to take into account time zones when you are communicating with your international trading partners.
Anyone working in Europe is generally 5-6 hours ahead, so start your day by speaking with them.
Use the mid-day to communicate with trading partners in your time zone and reserve the end of the day for business contacts on the West Coast of North America (who are three hours behind) or correspondence to contacts in Asia or Europe, who will see it first thing when they start their work day.