Basically just go on auction, Buy Now Minimum at 600 and Maximum at 650, and go and buy a bunch of Rare golds. Then do the same for Rare Silvers (250 Min, 300 Max), then regular golds (300 Min, 350 Max), and etc., until you have a ton of players.
I remember it took me to have about 800~900 club size before I got to 85 million. It takes a while, and you lose 50 coins for every card (if you just quick sell them all after you are done), but it's worth the trophy. --- Ben D Straw 6/29/08