Start with the most populous country. Then guess its most populous neighbour. Then guess the most populous neighbor of that country, etc... When you reach a dead end, go back and choose the next most populous neighbor. Finally, when you're done with continents continue onto the island
Overseas territories don't count, but overseas regions do
Yes: France/Brazil, Morocco/Spain
No: France/Netherlands, UK/Spain, Sri Lanka/India, Qatar/UAE
Quiz idea from: https://www.jetpunk.com/user-quizzes/91108/country-neighbour-connect-by-northernmost-point
Belize should be before El Salvador (because it has a border with Mexico)
Poland should be followed by Russia, not Ukraine
Hungary should be followed by the Czech Republic, not Austria
Vatican city should be followed by Slovenia, because it shares a border with Italy