my strategy with altcoins are very simple. When my coin 2x in price, i just sell 50% i.e i take out my initial investment. In that way i ensure no loss. The according to market i can plan when i need to sell the rest.
This is also a nice move not so greedy when it comes to taking profit when you have your coins. Sell it when it is the right time and the price already increases. Sometimes holding too long is not also a good choice except for bitcoin which ensures a good profit in the long run. This shows that we have to invest in what we can afford to lose since some coins are not profitable to hold long term.