If you hear a scholar gives evidences from Quran, Sunnah, and the righteous predecessors (salaf), you know that he is trustworthy and reliable. The country is not of great importance. It is the knowledge that counts. 

other than choosing a trustworthy, religiously-committed & knowledgeable scholar 2 clear religious doubts, is there any other criteria? For ex, is it better to consult a scholar of one’s own country as he’d b better informed of the situation we’re trying to get an answer to, our language and customs etc…