Even after you have established credit in a different country, you should maintain a credit history in the U.S. if you think you'll ever return.
"Pay all your bills," said CFP Maura Griffin, founder and CEO of Blue Spark Capital Advisors. "Keep your U.S. credit good.
"Make small charges, and pay them to keep a credit history," she added. Otherwise, you might struggle getting credit if you return to the U.S.
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Also, determine whether there are restrictions on anything valuable you want to bring into your destination country, whether it is a family heirloom or firearms. For instance, you might pay tax on valuables brought into a country, or you might end up relinquishing your firearms if you show up with them and they aren't permitted in the host country.
"Find out what is permissible," Leonard said. "Talking to a U.S. consulate where you're going is not a bad place to start."
—By Sarah O'Brien, special to CNBC.com