A smart way is buy when the price is dropping and sell it when the price is really high. I have heard that most of the people do this way to earn money from bitcoins.
I think this is a logical way to increase your money. I hope that i can try this more.
It's easy to say it, but we never know when the right time when prices fall and also when the right time when the price goes up. the point is we must have a target, then you can analyze and put at the right time. because sometimes when we greedy finally always regret it, because the price doesn't match the expectations.