Don't forget to register all new hardware.
Over the past year or so, Nintendo has allowed users to register their consoles and handhelds for coins, but only those released after the Nintendo DSi will earn them. This means you can register your Nintendo DSi, Nintendo DSi XL, or your Wii for coins, but only the black or white Wiis bundled with Wii Sports Resort will earn you coins.
Hardware can earn you quite a hefty amount of coins and can help you reach elite status a lot quicker than usual. If you bought a DSi XL it is worth 160 coins. The impending launch of the 3DS should get you a long way towards earning Platinum Level in the coming year.