Nothing. I don't do much trading but I have 1 main rule: You don't lose anything if you don't sell your coins. It works for me as I bought some coins and after that the price dropped nearly $50. But I simply kept holding, and right now that $50 price decrease is turned into a $110 price increase. 
It all depends on the situation. What looks bad today can look perfectly fine next week. It just shows that holding without selling in panic is the best thing to do. People that sell their coins in panic will surely end up buying back the coins they sold at a higher price.
Situation are the market: Never Against Market! Follow trend, use stop loss and fix a take profit. Take a look to support and resistance. If you have a big loss, stop trading for not less than 12 hours: don't try to increase risk for cover loss!
Then, as i say ( i trade Forex) is possible to make about 10% daily with low risk. (if intereste ask me how!)
Stop loss is definitely my favorite type of trading functionality. It saved me plenty of profits as the price went down a lot lower then my selling levels were. It allowed me to get a much better position in the market. I was doing intensive day trading back in 2013 and even a while in 2014 but I stopped doing it as I got tired or staring at the price tickers all day. My free time is much more important and valuable than a few tame profits that you get on low volume days.
. Sometimes i've some loss, and when it happens i go away for a pizza and a beer, and stop trade for not less tham 12 hours. 