My trading strategy is very simple and yet really effective. I only trade with coins which have a very high trading volume to ensure liquidity if my assets. This is the most important thing to look for in the coin you want to day trade.
Second, i only buy those coins which i think have alot of potential to grow in future. The crypto market is very volatile and anything can happen so if you choose wisely, you can also recover your trading loss by holding a progressive coin.
Fib ret (Fibonacci Retracement) is a tool used by many traders to choose the right coin to trade and you can easily use them to find a better coin. They basically use horizontal lines to indicate areas of support or resistance. You can refer to http://www.investopedia.com/terms/f/fibonacciretracement.asp for better understanding.