1) Use other exchanges when possible. Best for longer term standing limit orders / swing trades.
2) Bter dominates and has a large share of bot/arbitrage/hedging volume with MMC/CNY. This seems to lead to some predictable market effects. CNY has more volume due to it being more "certain" / stable to bots - these are open bot positions waiting to close...sell if MMC/CNY or MMC/BTC * BTC/CNY is greater than MMC/CNY when bought.
3) Use MMC/CNY for market orders if possible, and MMC/BTC for limit buy orders. "Human" MMC/CNY orders only sell on a BTC/CNY decrease (hurry and buy BTC), and MMC/BTC only sells on a BTC/CNY increase (hurry and sell BTC). Bots won't buy their own orders, which is why you sometimes see 0.2% spread on one market and 10% spread on another.
4) Do not place limit sell orders on Bter - use alternate exchanges for that. The bots on Bter will never execute them, except at a horrible price, and they'll only provide resistance (or worse, lead to gaps in bot orders and price jumps..). Bots will arbitrage the two markets to give huge spreads, which will only slowly fill in with BTC/CNY volatility, so no human will buy with the huge spread...
5) Overall, the spreads slowly refill with VWAP bots and hedges in other markets, etc. It's important to keep buy support in MMC/BTC...but price won't move until bots re-value VWAP on MMC/CNY. So, the best way to support price is in sets of three: Limit Bid MMC/BTC, Limit Bid MMC/CNY, Market Buy MMC/CNY