The only countries to avoid shipping to from USA are Italy and Peru (It’s illegal to send yoyos there, I kid you not)
Canada and the rest of the world are pretty easy. Like Miamibuddha showed, fill out the customs form, check gift, put an approximate amount (no duty unless over 10,000 dollars). Most international shipping rates are double what domestic rates are (rates went up, used to actually be cheaper to send to Canada).
That’s it. By the way, I ship internationally 