Today is the busiest pick-up day of the year for international-shipping giant DHL as businesses rush to have items delivered in time to be under the tree on Christmas morning.

Monday Dec. 17 is the busiest day for DHL to make drop-offs. Plantation, Fla.-based DHL does only international shipping and hasn't had a domestic service since 2009. Federal Express and the United Parcel Service dominate those markets.

While delivery times vary depending on how far an item needs to go, it is best to get an item out the door by Dec. 17, to help ensure it gets there by Christmas, according to John Fox, the general manager of the Southeast for DHL.  

An increasing number of entrepreneurs are looking to find new customers by going overseas, Fox says. If you have overseas customers, consider the following five ways to keep your global shipping running smoothly and stress-free.

1. Take pains with your packaging. Make sure that you are packing your goods in new containers that are appropriate for the item being shipped. If the item is breakable, be sure to have two inches of bubble-wrap or styrofoam between the item and the box, Fox says. 

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2. Be especially clear on outside labels about what is inside each box. For international shipping, it is critical that you provide detailed descriptions of exactly what is in your package for the sake of customs agents. Also, the values attributed to your items must be very accurate. If you are not clear, it simply creates the opportunity for a delay, Fox says.

3. Consider using your shipper's online tools. Every country you ship to will have a unique set of requirements for items being received from another country. Having a web-based tool can help streamline the compliance process. DHL’s web-based tool, for example, electronically transmits necessary forms from the country of origin to the receiving country to speed up the process ahead of the package’s arrival.

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4. Provide complete addresses and contact information. “You would be surprised how often incomplete or inaccurate addresses are provided and contact information for the receiver and the sender,” Fox says. Be especially careful with postal codes, he adds.

5. Be sure that what you are sending is not illegal to ship. Think twice before shipping your aunt in London some new perfume. Flammable goods -- like perfume and hairspray -- are considered dangerous. Some regulated goods, including dangerous products, but also some surprising items such as perfumes and battery operated toys, either cannot be shipped at all or require additional documentation. Best just leave anything especially risky to Santa Claus and his reindeer.

Related: 10 Questions Every Entrepreneur Needs to Ask Suppliers

What is the most important piece of advice your business has learned about shipping overseas? Leave a comment and let us know.