I don't really have a strategy that I use. I just buy some Bitcoins every now and then when the price has gone down to hold for the long term. That's all I do at the moment. I am not even trading. It's purely holding what I do. I am so happy with my Bitcoin investment that I never look into any other investment. Bitcoin is more than enough for me as I believe in its full future potential.
I think the best investment strategy is that, be familiarize in bitcoin in terms of investment before you invest of course. Then engage and hold and wait until the value reaches your contentment. The best time to buy btc is when it drops it value. And the best time to sell is when the value rises up.