This is my method in earning bitcoin. I go for forum site and faucet site for earning capital funds. Then invest my bitcoin to online investment site. Other option is trade my bitcoin in trading site. Buy for stacks and sell it as price is up. And last option is gambling I try my luck to bet to grow my bitcoins.
The easiest way to earn bitcoin here, I think you must need to trade your coin in the exchange to grow it more faster. Or you participate in the signature campaign too.