Subnetting questions for ccna

I think I have finally cracked these now and can pretty much do them in my head quite quickly.

However, with design questions where you need X subnets with Y hosts, do you answer with the theoretical minimum mask that would meet the needs of the question?

If the minimum theoretical subnet range would leave it very limited in growth potential, would the correct answer be to take that into account and answer with a mask that would easily cover whats required giving room for growth?

Anyone any ideas?

From what I've seen till now, the exam questions usually indicate which thing should you minimize or maximize (the subnets or hosts). Wither directly or indirectly there is an indication.