investing on mining, make sure to select mining site that are on business 3 or more years already.. small income but harvest it years from now.

 hoarding, just let your btc sleep in your wallet it will go up in time as btc rise up in value theres no stopping it.

I think if you want to increase your bitcoin in a safer way try to do some trading, all you need is capital and buy some cheap coins but before you buy it do some research so make sure that the atlcoin that you will buy is legit and not a scam. For me trading is a lot safer than gambling or investing on different HYIPs out there that are getting scam faster than before.