Conduct good global keyword research. Google will tell you what people are searching for in different countries. Use the Google trend tool and you will see a bar chart of the search volume by country for a given search word. When you find a good keyword set (words with broad appeal in several countries), focus on those keywords in your hub. Watch the keyword stats on your hubs and you can see which countries people are using to find your hub. For example, on one of my hubs, I noticed that a number of people found the hub on google.no (this means it's Google in Norway).
Hope that helps.