It's a trial and error process, to be honest.
You have to find certain indicators that will fit your trading style, and that will cost you x amount of funds in order to apply the indicators you want to find the right ones for you. Now, for me, using only one won't work, I'm using at least 3 indicators, you have to make sure your price chart is readable for you to be able to see in which price or point you're going to enter your trade.
If the indicator is not working, you have to use the other one and yes this is a trial and error until you make a good one. Knowing many indicators as much as possible is advisable since not all can work effectively and you have to find a good alternative. I’ve been trading with a different strategies depends on how the market trend behave, usually 2 to 3 indicators are already fine and you can already see the blue print of the trend, and from there you can start doing your own trading strategy.